Version:  2.0.40 2.2.26 2.4.37 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 4.8

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 <linux/dynamic_debug.h>
 64 #include <uapi/linux/module.h>
 65 #include "module-internal.h"
 66 
 67 #define CREATE_TRACE_POINTS
 68 #include <trace/events/module.h>
 69 
 70 #ifndef ARCH_SHF_SMALL
 71 #define ARCH_SHF_SMALL 0
 72 #endif
 73 
 74 /*
 75  * Modules' sections will be aligned on page boundaries
 76  * to ensure complete separation of code and data, but
 77  * only when CONFIG_DEBUG_SET_MODULE_RONX=y
 78  */
 79 #ifdef CONFIG_DEBUG_SET_MODULE_RONX
 80 # define debug_align(X) ALIGN(X, PAGE_SIZE)
 81 #else
 82 # define debug_align(X) (X)
 83 #endif
 84 
 85 /* If this is set, the section belongs in the init part of the module */
 86 #define INIT_OFFSET_MASK (1UL << (BITS_PER_LONG-1))
 87 
 88 /*
 89  * Mutex protects:
 90  * 1) List of modules (also safely readable with preempt_disable),
 91  * 2) module_use links,
 92  * 3) module_addr_min/module_addr_max.
 93  * (delete and add uses RCU list operations). */
 94 DEFINE_MUTEX(module_mutex);
 95 EXPORT_SYMBOL_GPL(module_mutex);
 96 static LIST_HEAD(modules);
 97 
 98 #ifdef CONFIG_MODULES_TREE_LOOKUP
 99 
100 /*
101  * Use a latched RB-tree for __module_address(); this allows us to use
102  * RCU-sched lookups of the address from any context.
103  *
104  * This is conditional on PERF_EVENTS || TRACING because those can really hit
105  * __module_address() hard by doing a lot of stack unwinding; potentially from
106  * NMI context.
107  */
108 
109 static __always_inline unsigned long __mod_tree_val(struct latch_tree_node *n)
110 {
111         struct module_layout *layout = container_of(n, struct module_layout, mtn.node);
112 
113         return (unsigned long)layout->base;
114 }
115 
116 static __always_inline unsigned long __mod_tree_size(struct latch_tree_node *n)
117 {
118         struct module_layout *layout = container_of(n, struct module_layout, mtn.node);
119 
120         return (unsigned long)layout->size;
121 }
122 
123 static __always_inline bool
124 mod_tree_less(struct latch_tree_node *a, struct latch_tree_node *b)
125 {
126         return __mod_tree_val(a) < __mod_tree_val(b);
127 }
128 
129 static __always_inline int
130 mod_tree_comp(void *key, struct latch_tree_node *n)
131 {
132         unsigned long val = (unsigned long)key;
133         unsigned long start, end;
134 
135         start = __mod_tree_val(n);
136         if (val < start)
137                 return -1;
138 
139         end = start + __mod_tree_size(n);
140         if (val >= end)
141                 return 1;
142 
143         return 0;
144 }
145 
146 static const struct latch_tree_ops mod_tree_ops = {
147         .less = mod_tree_less,
148         .comp = mod_tree_comp,
149 };
150 
151 static struct mod_tree_root {
152         struct latch_tree_root root;
153         unsigned long addr_min;
154         unsigned long addr_max;
155 } mod_tree __cacheline_aligned = {
156         .addr_min = -1UL,
157 };
158 
159 #define module_addr_min mod_tree.addr_min
160 #define module_addr_max mod_tree.addr_max
161 
162 static noinline void __mod_tree_insert(struct mod_tree_node *node)
163 {
164         latch_tree_insert(&node->node, &mod_tree.root, &mod_tree_ops);
165 }
166 
167 static void __mod_tree_remove(struct mod_tree_node *node)
168 {
169         latch_tree_erase(&node->node, &mod_tree.root, &mod_tree_ops);
170 }
171 
172 /*
173  * These modifications: insert, remove_init and remove; are serialized by the
174  * module_mutex.
175  */
176 static void mod_tree_insert(struct module *mod)
177 {
178         mod->core_layout.mtn.mod = mod;
179         mod->init_layout.mtn.mod = mod;
180 
181         __mod_tree_insert(&mod->core_layout.mtn);
182         if (mod->init_layout.size)
183                 __mod_tree_insert(&mod->init_layout.mtn);
184 }
185 
186 static void mod_tree_remove_init(struct module *mod)
187 {
188         if (mod->init_layout.size)
189                 __mod_tree_remove(&mod->init_layout.mtn);
190 }
191 
192 static void mod_tree_remove(struct module *mod)
193 {
194         __mod_tree_remove(&mod->core_layout.mtn);
195         mod_tree_remove_init(mod);
196 }
197 
198 static struct module *mod_find(unsigned long addr)
199 {
200         struct latch_tree_node *ltn;
201 
202         ltn = latch_tree_find((void *)addr, &mod_tree.root, &mod_tree_ops);
203         if (!ltn)
204                 return NULL;
205 
206         return container_of(ltn, struct mod_tree_node, node)->mod;
207 }
208 
209 #else /* MODULES_TREE_LOOKUP */
210 
211 static unsigned long module_addr_min = -1UL, module_addr_max = 0;
212 
213 static void mod_tree_insert(struct module *mod) { }
214 static void mod_tree_remove_init(struct module *mod) { }
215 static void mod_tree_remove(struct module *mod) { }
216 
217 static struct module *mod_find(unsigned long addr)
218 {
219         struct module *mod;
220 
221         list_for_each_entry_rcu(mod, &modules, list) {
222                 if (within_module(addr, mod))
223                         return mod;
224         }
225 
226         return NULL;
227 }
228 
229 #endif /* MODULES_TREE_LOOKUP */
230 
231 /*
232  * Bounds of module text, for speeding up __module_address.
233  * Protected by module_mutex.
234  */
235 static void __mod_update_bounds(void *base, unsigned int size)
236 {
237         unsigned long min = (unsigned long)base;
238         unsigned long max = min + size;
239 
240         if (min < module_addr_min)
241                 module_addr_min = min;
242         if (max > module_addr_max)
243                 module_addr_max = max;
244 }
245 
246 static void mod_update_bounds(struct module *mod)
247 {
248         __mod_update_bounds(mod->core_layout.base, mod->core_layout.size);
249         if (mod->init_layout.size)
250                 __mod_update_bounds(mod->init_layout.base, mod->init_layout.size);
251 }
252 
253 #ifdef CONFIG_KGDB_KDB
254 struct list_head *kdb_modules = &modules; /* kdb needs the list of modules */
255 #endif /* CONFIG_KGDB_KDB */
256 
257 static void module_assert_mutex(void)
258 {
259         lockdep_assert_held(&module_mutex);
260 }
261 
262 static void module_assert_mutex_or_preempt(void)
263 {
264 #ifdef CONFIG_LOCKDEP
265         if (unlikely(!debug_locks))
266                 return;
267 
268         WARN_ON_ONCE(!rcu_read_lock_sched_held() &&
269                 !lockdep_is_held(&module_mutex));
270 #endif
271 }
272 
273 static bool sig_enforce = IS_ENABLED(CONFIG_MODULE_SIG_FORCE);
274 #ifndef CONFIG_MODULE_SIG_FORCE
275 module_param(sig_enforce, bool_enable_only, 0644);
276 #endif /* !CONFIG_MODULE_SIG_FORCE */
277 
278 /* Block module loading/unloading? */
279 int modules_disabled = 0;
280 core_param(nomodule, modules_disabled, bint, 0);
281 
282 /* Waiting for a module to finish initializing? */
283 static DECLARE_WAIT_QUEUE_HEAD(module_wq);
284 
285 static BLOCKING_NOTIFIER_HEAD(module_notify_list);
286 
287 int register_module_notifier(struct notifier_block *nb)
288 {
289         return blocking_notifier_chain_register(&module_notify_list, nb);
290 }
291 EXPORT_SYMBOL(register_module_notifier);
292 
293 int unregister_module_notifier(struct notifier_block *nb)
294 {
295         return blocking_notifier_chain_unregister(&module_notify_list, nb);
296 }
297 EXPORT_SYMBOL(unregister_module_notifier);
298 
299 struct load_info {
300         Elf_Ehdr *hdr;
301         unsigned long len;
302         Elf_Shdr *sechdrs;
303         char *secstrings, *strtab;
304         unsigned long symoffs, stroffs;
305         struct _ddebug *debug;
306         unsigned int num_debug;
307         bool sig_ok;
308 #ifdef CONFIG_KALLSYMS
309         unsigned long mod_kallsyms_init_off;
310 #endif
311         struct {
312                 unsigned int sym, str, mod, vers, info, pcpu;
313         } index;
314 };
315 
316 /* We require a truly strong try_module_get(): 0 means failure due to
317    ongoing or failed initialization etc. */
318 static inline int strong_try_module_get(struct module *mod)
319 {
320         BUG_ON(mod && mod->state == MODULE_STATE_UNFORMED);
321         if (mod && mod->state == MODULE_STATE_COMING)
322                 return -EBUSY;
323         if (try_module_get(mod))
324                 return 0;
325         else
326                 return -ENOENT;
327 }
328 
329 static inline void add_taint_module(struct module *mod, unsigned flag,
330                                     enum lockdep_ok lockdep_ok)
331 {
332         add_taint(flag, lockdep_ok);
333         mod->taints |= (1U << flag);
334 }
335 
336 /*
337  * A thread that wants to hold a reference to a module only while it
338  * is running can call this to safely exit.  nfsd and lockd use this.
339  */
340 void __noreturn __module_put_and_exit(struct module *mod, long code)
341 {
342         module_put(mod);
343         do_exit(code);
344 }
345 EXPORT_SYMBOL(__module_put_and_exit);
346 
347 /* Find a module section: 0 means not found. */
348 static unsigned int find_sec(const struct load_info *info, const char *name)
349 {
350         unsigned int i;
351 
352         for (i = 1; i < info->hdr->e_shnum; i++) {
353                 Elf_Shdr *shdr = &info->sechdrs[i];
354                 /* Alloc bit cleared means "ignore it." */
355                 if ((shdr->sh_flags & SHF_ALLOC)
356                     && strcmp(info->secstrings + shdr->sh_name, name) == 0)
357                         return i;
358         }
359         return 0;
360 }
361 
362 /* Find a module section, or NULL. */
363 static void *section_addr(const struct load_info *info, const char *name)
364 {
365         /* Section 0 has sh_addr 0. */
366         return (void *)info->sechdrs[find_sec(info, name)].sh_addr;
367 }
368 
369 /* Find a module section, or NULL.  Fill in number of "objects" in section. */
370 static void *section_objs(const struct load_info *info,
371                           const char *name,
372                           size_t object_size,
373                           unsigned int *num)
374 {
375         unsigned int sec = find_sec(info, name);
376 
377         /* Section 0 has sh_addr 0 and sh_size 0. */
378         *num = info->sechdrs[sec].sh_size / object_size;
379         return (void *)info->sechdrs[sec].sh_addr;
380 }
381 
382 /* Provided by the linker */
383 extern const struct kernel_symbol __start___ksymtab[];
384 extern const struct kernel_symbol __stop___ksymtab[];
385 extern const struct kernel_symbol __start___ksymtab_gpl[];
386 extern const struct kernel_symbol __stop___ksymtab_gpl[];
387 extern const struct kernel_symbol __start___ksymtab_gpl_future[];
388 extern const struct kernel_symbol __stop___ksymtab_gpl_future[];
389 extern const unsigned long __start___kcrctab[];
390 extern const unsigned long __start___kcrctab_gpl[];
391 extern const unsigned long __start___kcrctab_gpl_future[];
392 #ifdef CONFIG_UNUSED_SYMBOLS
393 extern const struct kernel_symbol __start___ksymtab_unused[];
394 extern const struct kernel_symbol __stop___ksymtab_unused[];
395 extern const struct kernel_symbol __start___ksymtab_unused_gpl[];
396 extern const struct kernel_symbol __stop___ksymtab_unused_gpl[];
397 extern const unsigned long __start___kcrctab_unused[];
398 extern const unsigned long __start___kcrctab_unused_gpl[];
399 #endif
400 
401 #ifndef CONFIG_MODVERSIONS
402 #define symversion(base, idx) NULL
403 #else
404 #define symversion(base, idx) ((base != NULL) ? ((base) + (idx)) : NULL)
405 #endif
406 
407 static bool each_symbol_in_section(const struct symsearch *arr,
408                                    unsigned int arrsize,
409                                    struct module *owner,
410                                    bool (*fn)(const struct symsearch *syms,
411                                               struct module *owner,
412                                               void *data),
413                                    void *data)
414 {
415         unsigned int j;
416 
417         for (j = 0; j < arrsize; j++) {
418                 if (fn(&arr[j], owner, data))
419                         return true;
420         }
421 
422         return false;
423 }
424 
425 /* Returns true as soon as fn returns true, otherwise false. */
426 bool each_symbol_section(bool (*fn)(const struct symsearch *arr,
427                                     struct module *owner,
428                                     void *data),
429                          void *data)
430 {
431         struct module *mod;
432         static const struct symsearch arr[] = {
433                 { __start___ksymtab, __stop___ksymtab, __start___kcrctab,
434                   NOT_GPL_ONLY, false },
435                 { __start___ksymtab_gpl, __stop___ksymtab_gpl,
436                   __start___kcrctab_gpl,
437                   GPL_ONLY, false },
438                 { __start___ksymtab_gpl_future, __stop___ksymtab_gpl_future,
439                   __start___kcrctab_gpl_future,
440                   WILL_BE_GPL_ONLY, false },
441 #ifdef CONFIG_UNUSED_SYMBOLS
442                 { __start___ksymtab_unused, __stop___ksymtab_unused,
443                   __start___kcrctab_unused,
444                   NOT_GPL_ONLY, true },
445                 { __start___ksymtab_unused_gpl, __stop___ksymtab_unused_gpl,
446                   __start___kcrctab_unused_gpl,
447                   GPL_ONLY, true },
448 #endif
449         };
450 
451         module_assert_mutex_or_preempt();
452 
453         if (each_symbol_in_section(arr, ARRAY_SIZE(arr), NULL, fn, data))
454                 return true;
455 
456         list_for_each_entry_rcu(mod, &modules, list) {
457                 struct symsearch arr[] = {
458                         { mod->syms, mod->syms + mod->num_syms, mod->crcs,
459                           NOT_GPL_ONLY, false },
460                         { mod->gpl_syms, mod->gpl_syms + mod->num_gpl_syms,
461                           mod->gpl_crcs,
462                           GPL_ONLY, false },
463                         { mod->gpl_future_syms,
464                           mod->gpl_future_syms + mod->num_gpl_future_syms,
465                           mod->gpl_future_crcs,
466                           WILL_BE_GPL_ONLY, false },
467 #ifdef CONFIG_UNUSED_SYMBOLS
468                         { mod->unused_syms,
469                           mod->unused_syms + mod->num_unused_syms,
470                           mod->unused_crcs,
471                           NOT_GPL_ONLY, true },
472                         { mod->unused_gpl_syms,
473                           mod->unused_gpl_syms + mod->num_unused_gpl_syms,
474                           mod->unused_gpl_crcs,
475                           GPL_ONLY, true },
476 #endif
477                 };
478 
479                 if (mod->state == MODULE_STATE_UNFORMED)
480                         continue;
481 
482                 if (each_symbol_in_section(arr, ARRAY_SIZE(arr), mod, fn, data))
483                         return true;
484         }
485         return false;
486 }
487 EXPORT_SYMBOL_GPL(each_symbol_section);
488 
489 struct find_symbol_arg {
490         /* Input */
491         const char *name;
492         bool gplok;
493         bool warn;
494 
495         /* Output */
496         struct module *owner;
497         const unsigned long *crc;
498         const struct kernel_symbol *sym;
499 };
500 
501 static bool check_symbol(const struct symsearch *syms,
502                                  struct module *owner,
503                                  unsigned int symnum, void *data)
504 {
505         struct find_symbol_arg *fsa = data;
506 
507         if (!fsa->gplok) {
508                 if (syms->licence == GPL_ONLY)
509                         return false;
510                 if (syms->licence == WILL_BE_GPL_ONLY && fsa->warn) {
511                         pr_warn("Symbol %s is being used by a non-GPL module, "
512                                 "which will not be allowed in the future\n",
513                                 fsa->name);
514                 }
515         }
516 
517 #ifdef CONFIG_UNUSED_SYMBOLS
518         if (syms->unused && fsa->warn) {
519                 pr_warn("Symbol %s is marked as UNUSED, however this module is "
520                         "using it.\n", fsa->name);
521                 pr_warn("This symbol will go away in the future.\n");
522                 pr_warn("Please evaluate if this is the right api to use and "
523                         "if it really is, submit a report to the linux kernel "
524                         "mailing list together with submitting your code for "
525                         "inclusion.\n");
526         }
527 #endif
528 
529         fsa->owner = owner;
530         fsa->crc = symversion(syms->crcs, symnum);
531         fsa->sym = &syms->start[symnum];
532         return true;
533 }
534 
535 static int cmp_name(const void *va, const void *vb)
536 {
537         const char *a;
538         const struct kernel_symbol *b;
539         a = va; b = vb;
540         return strcmp(a, b->name);
541 }
542 
543 static bool find_symbol_in_section(const struct symsearch *syms,
544                                    struct module *owner,
545                                    void *data)
546 {
547         struct find_symbol_arg *fsa = data;
548         struct kernel_symbol *sym;
549 
550         sym = bsearch(fsa->name, syms->start, syms->stop - syms->start,
551                         sizeof(struct kernel_symbol), cmp_name);
552 
553         if (sym != NULL && check_symbol(syms, owner, sym - syms->start, data))
554                 return true;
555 
556         return false;
557 }
558 
559 /* Find a symbol and return it, along with, (optional) crc and
560  * (optional) module which owns it.  Needs preempt disabled or module_mutex. */
561 const struct kernel_symbol *find_symbol(const char *name,
562                                         struct module **owner,
563                                         const unsigned long **crc,
564                                         bool gplok,
565                                         bool warn)
566 {
567         struct find_symbol_arg fsa;
568 
569         fsa.name = name;
570         fsa.gplok = gplok;
571         fsa.warn = warn;
572 
573         if (each_symbol_section(find_symbol_in_section, &fsa)) {
574                 if (owner)
575                         *owner = fsa.owner;
576                 if (crc)
577                         *crc = fsa.crc;
578                 return fsa.sym;
579         }
580 
581         pr_debug("Failed to find symbol %s\n", name);
582         return NULL;
583 }
584 EXPORT_SYMBOL_GPL(find_symbol);
585 
586 /*
587  * Search for module by name: must hold module_mutex (or preempt disabled
588  * for read-only access).
589  */
590 static struct module *find_module_all(const char *name, size_t len,
591                                       bool even_unformed)
592 {
593         struct module *mod;
594 
595         module_assert_mutex_or_preempt();
596 
597         list_for_each_entry(mod, &modules, list) {
598                 if (!even_unformed && mod->state == MODULE_STATE_UNFORMED)
599                         continue;
600                 if (strlen(mod->name) == len && !memcmp(mod->name, name, len))
601                         return mod;
602         }
603         return NULL;
604 }
605 
606 struct module *find_module(const char *name)
607 {
608         module_assert_mutex();
609         return find_module_all(name, strlen(name), false);
610 }
611 EXPORT_SYMBOL_GPL(find_module);
612 
613 #ifdef CONFIG_SMP
614 
615 static inline void __percpu *mod_percpu(struct module *mod)
616 {
617         return mod->percpu;
618 }
619 
620 static int percpu_modalloc(struct module *mod, struct load_info *info)
621 {
622         Elf_Shdr *pcpusec = &info->sechdrs[info->index.pcpu];
623         unsigned long align = pcpusec->sh_addralign;
624 
625         if (!pcpusec->sh_size)
626                 return 0;
627 
628         if (align > PAGE_SIZE) {
629                 pr_warn("%s: per-cpu alignment %li > %li\n",
630                         mod->name, align, PAGE_SIZE);
631                 align = PAGE_SIZE;
632         }
633 
634         mod->percpu = __alloc_reserved_percpu(pcpusec->sh_size, align);
635         if (!mod->percpu) {
636                 pr_warn("%s: Could not allocate %lu bytes percpu data\n",
637                         mod->name, (unsigned long)pcpusec->sh_size);
638                 return -ENOMEM;
639         }
640         mod->percpu_size = pcpusec->sh_size;
641         return 0;
642 }
643 
644 static void percpu_modfree(struct module *mod)
645 {
646         free_percpu(mod->percpu);
647 }
648 
649 static unsigned int find_pcpusec(struct load_info *info)
650 {
651         return find_sec(info, ".data..percpu");
652 }
653 
654 static void percpu_modcopy(struct module *mod,
655                            const void *from, unsigned long size)
656 {
657         int cpu;
658 
659         for_each_possible_cpu(cpu)
660                 memcpy(per_cpu_ptr(mod->percpu, cpu), from, size);
661 }
662 
663 /**
664  * is_module_percpu_address - test whether address is from module static percpu
665  * @addr: address to test
666  *
667  * Test whether @addr belongs to module static percpu area.
668  *
669  * RETURNS:
670  * %true if @addr is from module static percpu area
671  */
672 bool is_module_percpu_address(unsigned long addr)
673 {
674         struct module *mod;
675         unsigned int cpu;
676 
677         preempt_disable();
678 
679         list_for_each_entry_rcu(mod, &modules, list) {
680                 if (mod->state == MODULE_STATE_UNFORMED)
681                         continue;
682                 if (!mod->percpu_size)
683                         continue;
684                 for_each_possible_cpu(cpu) {
685                         void *start = per_cpu_ptr(mod->percpu, cpu);
686 
687                         if ((void *)addr >= start &&
688                             (void *)addr < start + mod->percpu_size) {
689                                 preempt_enable();
690                                 return true;
691                         }
692                 }
693         }
694 
695         preempt_enable();
696         return false;
697 }
698 
699 #else /* ... !CONFIG_SMP */
700 
701 static inline void __percpu *mod_percpu(struct module *mod)
702 {
703         return NULL;
704 }
705 static int percpu_modalloc(struct module *mod, struct load_info *info)
706 {
707         /* UP modules shouldn't have this section: ENOMEM isn't quite right */
708         if (info->sechdrs[info->index.pcpu].sh_size != 0)
709                 return -ENOMEM;
710         return 0;
711 }
712 static inline void percpu_modfree(struct module *mod)
713 {
714 }
715 static unsigned int find_pcpusec(struct load_info *info)
716 {
717         return 0;
718 }
719 static inline void percpu_modcopy(struct module *mod,
720                                   const void *from, unsigned long size)
721 {
722         /* pcpusec should be 0, and size of that section should be 0. */
723         BUG_ON(size != 0);
724 }
725 bool is_module_percpu_address(unsigned long addr)
726 {
727         return false;
728 }
729 
730 #endif /* CONFIG_SMP */
731 
732 #define MODINFO_ATTR(field)     \
733 static void setup_modinfo_##field(struct module *mod, const char *s)  \
734 {                                                                     \
735         mod->field = kstrdup(s, GFP_KERNEL);                          \
736 }                                                                     \
737 static ssize_t show_modinfo_##field(struct module_attribute *mattr,   \
738                         struct module_kobject *mk, char *buffer)      \
739 {                                                                     \
740         return scnprintf(buffer, PAGE_SIZE, "%s\n", mk->mod->field);  \
741 }                                                                     \
742 static int modinfo_##field##_exists(struct module *mod)               \
743 {                                                                     \
744         return mod->field != NULL;                                    \
745 }                                                                     \
746 static void free_modinfo_##field(struct module *mod)                  \
747 {                                                                     \
748         kfree(mod->field);                                            \
749         mod->field = NULL;                                            \
750 }                                                                     \
751 static struct module_attribute modinfo_##field = {                    \
752         .attr = { .name = __stringify(field), .mode = 0444 },         \
753         .show = show_modinfo_##field,                                 \
754         .setup = setup_modinfo_##field,                               \
755         .test = modinfo_##field##_exists,                             \
756         .free = free_modinfo_##field,                                 \
757 };
758 
759 MODINFO_ATTR(version);
760 MODINFO_ATTR(srcversion);
761 
762 static char last_unloaded_module[MODULE_NAME_LEN+1];
763 
764 #ifdef CONFIG_MODULE_UNLOAD
765 
766 EXPORT_TRACEPOINT_SYMBOL(module_get);
767 
768 /* MODULE_REF_BASE is the base reference count by kmodule loader. */
769 #define MODULE_REF_BASE 1
770 
771 /* Init the unload section of the module. */
772 static int module_unload_init(struct module *mod)
773 {
774         /*
775          * Initialize reference counter to MODULE_REF_BASE.
776          * refcnt == 0 means module is going.
777          */
778         atomic_set(&mod->refcnt, MODULE_REF_BASE);
779 
780         INIT_LIST_HEAD(&mod->source_list);
781         INIT_LIST_HEAD(&mod->target_list);
782 
783         /* Hold reference count during initialization. */
784         atomic_inc(&mod->refcnt);
785 
786         return 0;
787 }
788 
789 /* Does a already use b? */
790 static int already_uses(struct module *a, struct module *b)
791 {
792         struct module_use *use;
793 
794         list_for_each_entry(use, &b->source_list, source_list) {
795                 if (use->source == a) {
796                         pr_debug("%s uses %s!\n", a->name, b->name);
797                         return 1;
798                 }
799         }
800         pr_debug("%s does not use %s!\n", a->name, b->name);
801         return 0;
802 }
803 
804 /*
805  * Module a uses b
806  *  - we add 'a' as a "source", 'b' as a "target" of module use
807  *  - the module_use is added to the list of 'b' sources (so
808  *    'b' can walk the list to see who sourced them), and of 'a'
809  *    targets (so 'a' can see what modules it targets).
810  */
811 static int add_module_usage(struct module *a, struct module *b)
812 {
813         struct module_use *use;
814 
815         pr_debug("Allocating new usage for %s.\n", a->name);
816         use = kmalloc(sizeof(*use), GFP_ATOMIC);
817         if (!use) {
818                 pr_warn("%s: out of memory loading\n", a->name);
819                 return -ENOMEM;
820         }
821 
822         use->source = a;
823         use->target = b;
824         list_add(&use->source_list, &b->source_list);
825         list_add(&use->target_list, &a->target_list);
826         return 0;
827 }
828 
829 /* Module a uses b: caller needs module_mutex() */
830 int ref_module(struct module *a, struct module *b)
831 {
832         int err;
833 
834         if (b == NULL || already_uses(a, b))
835                 return 0;
836 
837         /* If module isn't available, we fail. */
838         err = strong_try_module_get(b);
839         if (err)
840                 return err;
841 
842         err = add_module_usage(a, b);
843         if (err) {
844                 module_put(b);
845                 return err;
846         }
847         return 0;
848 }
849 EXPORT_SYMBOL_GPL(ref_module);
850 
851 /* Clear the unload stuff of the module. */
852 static void module_unload_free(struct module *mod)
853 {
854         struct module_use *use, *tmp;
855 
856         mutex_lock(&module_mutex);
857         list_for_each_entry_safe(use, tmp, &mod->target_list, target_list) {
858                 struct module *i = use->target;
859                 pr_debug("%s unusing %s\n", mod->name, i->name);
860                 module_put(i);
861                 list_del(&use->source_list);
862                 list_del(&use->target_list);
863                 kfree(use);
864         }
865         mutex_unlock(&module_mutex);
866 }
867 
868 #ifdef CONFIG_MODULE_FORCE_UNLOAD
869 static inline int try_force_unload(unsigned int flags)
870 {
871         int ret = (flags & O_TRUNC);
872         if (ret)
873                 add_taint(TAINT_FORCED_RMMOD, LOCKDEP_NOW_UNRELIABLE);
874         return ret;
875 }
876 #else
877 static inline int try_force_unload(unsigned int flags)
878 {
879         return 0;
880 }
881 #endif /* CONFIG_MODULE_FORCE_UNLOAD */
882 
883 /* Try to release refcount of module, 0 means success. */
884 static int try_release_module_ref(struct module *mod)
885 {
886         int ret;
887 
888         /* Try to decrement refcnt which we set at loading */
889         ret = atomic_sub_return(MODULE_REF_BASE, &mod->refcnt);
890         BUG_ON(ret < 0);
891         if (ret)
892                 /* Someone can put this right now, recover with checking */
893                 ret = atomic_add_unless(&mod->refcnt, MODULE_REF_BASE, 0);
894 
895         return ret;
896 }
897 
898 static int try_stop_module(struct module *mod, int flags, int *forced)
899 {
900         /* If it's not unused, quit unless we're forcing. */
901         if (try_release_module_ref(mod) != 0) {
902                 *forced = try_force_unload(flags);
903                 if (!(*forced))
904                         return -EWOULDBLOCK;
905         }
906 
907         /* Mark it as dying. */
908         mod->state = MODULE_STATE_GOING;
909 
910         return 0;
911 }
912 
913 /**
914  * module_refcount - return the refcount or -1 if unloading
915  *
916  * @mod:        the module we're checking
917  *
918  * Returns:
919  *      -1 if the module is in the process of unloading
920  *      otherwise the number of references in the kernel to the module
921  */
922 int module_refcount(struct module *mod)
923 {
924         return atomic_read(&mod->refcnt) - MODULE_REF_BASE;
925 }
926 EXPORT_SYMBOL(module_refcount);
927 
928 /* This exists whether we can unload or not */
929 static void free_module(struct module *mod);
930 
931 SYSCALL_DEFINE2(delete_module, const char __user *, name_user,
932                 unsigned int, flags)
933 {
934         struct module *mod;
935         char name[MODULE_NAME_LEN];
936         int ret, forced = 0;
937 
938         if (!capable(CAP_SYS_MODULE) || modules_disabled)
939                 return -EPERM;
940 
941         if (strncpy_from_user(name, name_user, MODULE_NAME_LEN-1) < 0)
942                 return -EFAULT;
943         name[MODULE_NAME_LEN-1] = '\0';
944 
945         if (mutex_lock_interruptible(&module_mutex) != 0)
946                 return -EINTR;
947 
948         mod = find_module(name);
949         if (!mod) {
950                 ret = -ENOENT;
951                 goto out;
952         }
953 
954         if (!list_empty(&mod->source_list)) {
955                 /* Other modules depend on us: get rid of them first. */
956                 ret = -EWOULDBLOCK;
957                 goto out;
958         }
959 
960         /* Doing init or already dying? */
961         if (mod->state != MODULE_STATE_LIVE) {
962                 /* FIXME: if (force), slam module count damn the torpedoes */
963                 pr_debug("%s already dying\n", mod->name);
964                 ret = -EBUSY;
965                 goto out;
966         }
967 
968         /* If it has an init func, it must have an exit func to unload */
969         if (mod->init && !mod->exit) {
970                 forced = try_force_unload(flags);
971                 if (!forced) {
972                         /* This module can't be removed */
973                         ret = -EBUSY;
974                         goto out;
975                 }
976         }
977 
978         /* Stop the machine so refcounts can't move and disable module. */
979         ret = try_stop_module(mod, flags, &forced);
980         if (ret != 0)
981                 goto out;
982 
983         mutex_unlock(&module_mutex);
984         /* Final destruction now no one is using it. */
985         if (mod->exit != NULL)
986                 mod->exit();
987         blocking_notifier_call_chain(&module_notify_list,
988                                      MODULE_STATE_GOING, mod);
989         klp_module_going(mod);
990         ftrace_release_mod(mod);
991 
992         async_synchronize_full();
993 
994         /* Store the name of the last unloaded module for diagnostic purposes */
995         strlcpy(last_unloaded_module, mod->name, sizeof(last_unloaded_module));
996 
997         free_module(mod);
998         return 0;
999 out:
1000         mutex_unlock(&module_mutex);
1001         return ret;
1002 }
1003 
1004 static inline void print_unload_info(struct seq_file *m, struct module *mod)
1005 {
1006         struct module_use *use;
1007         int printed_something = 0;
1008 
1009         seq_printf(m, " %i ", module_refcount(mod));
1010 
1011         /*
1012          * Always include a trailing , so userspace can differentiate
1013          * between this and the old multi-field proc format.
1014          */
1015         list_for_each_entry(use, &mod->source_list, source_list) {
1016                 printed_something = 1;
1017                 seq_printf(m, "%s,", use->source->name);
1018         }
1019 
1020         if (mod->init != NULL && mod->exit == NULL) {
1021                 printed_something = 1;
1022                 seq_puts(m, "[permanent],");
1023         }
1024 
1025         if (!printed_something)
1026                 seq_puts(m, "-");
1027 }
1028 
1029 void __symbol_put(const char *symbol)
1030 {
1031         struct module *owner;
1032 
1033         preempt_disable();
1034         if (!find_symbol(symbol, &owner, NULL, true, false))
1035                 BUG();
1036         module_put(owner);
1037         preempt_enable();
1038 }
1039 EXPORT_SYMBOL(__symbol_put);
1040 
1041 /* Note this assumes addr is a function, which it currently always is. */
1042 void symbol_put_addr(void *addr)
1043 {
1044         struct module *modaddr;
1045         unsigned long a = (unsigned long)dereference_function_descriptor(addr);
1046 
1047         if (core_kernel_text(a))
1048                 return;
1049 
1050         /*
1051          * Even though we hold a reference on the module; we still need to
1052          * disable preemption in order to safely traverse the data structure.
1053          */
1054         preempt_disable();
1055         modaddr = __module_text_address(a);
1056         BUG_ON(!modaddr);
1057         module_put(modaddr);
1058         preempt_enable();
1059 }
1060 EXPORT_SYMBOL_GPL(symbol_put_addr);
1061 
1062 static ssize_t show_refcnt(struct module_attribute *mattr,
1063                            struct module_kobject *mk, char *buffer)
1064 {
1065         return sprintf(buffer, "%i\n", module_refcount(mk->mod));
1066 }
1067 
1068 static struct module_attribute modinfo_refcnt =
1069         __ATTR(refcnt, 0444, show_refcnt, NULL);
1070 
1071 void __module_get(struct module *module)
1072 {
1073         if (module) {
1074                 preempt_disable();
1075                 atomic_inc(&module->refcnt);
1076                 trace_module_get(module, _RET_IP_);
1077                 preempt_enable();
1078         }
1079 }
1080 EXPORT_SYMBOL(__module_get);
1081 
1082 bool try_module_get(struct module *module)
1083 {
1084         bool ret = true;
1085 
1086         if (module) {
1087                 preempt_disable();
1088                 /* Note: here, we can fail to get a reference */
1089                 if (likely(module_is_live(module) &&
1090                            atomic_inc_not_zero(&module->refcnt) != 0))
1091                         trace_module_get(module, _RET_IP_);
1092                 else
1093                         ret = false;
1094 
1095                 preempt_enable();
1096         }
1097         return ret;
1098 }
1099 EXPORT_SYMBOL(try_module_get);
1100 
1101 void module_put(struct module *module)
1102 {
1103         int ret;
1104 
1105         if (module) {
1106                 preempt_disable();
1107                 ret = atomic_dec_if_positive(&module->refcnt);
1108                 WARN_ON(ret < 0);       /* Failed to put refcount */
1109                 trace_module_put(module, _RET_IP_);
1110                 preempt_enable();
1111         }
1112 }
1113 EXPORT_SYMBOL(module_put);
1114 
1115 #else /* !CONFIG_MODULE_UNLOAD */
1116 static inline void print_unload_info(struct seq_file *m, struct module *mod)
1117 {
1118         /* We don't know the usage count, or what modules are using. */
1119         seq_puts(m, " - -");
1120 }
1121 
1122 static inline void module_unload_free(struct module *mod)
1123 {
1124 }
1125 
1126 int ref_module(struct module *a, struct module *b)
1127 {
1128         return strong_try_module_get(b);
1129 }
1130 EXPORT_SYMBOL_GPL(ref_module);
1131 
1132 static inline int module_unload_init(struct module *mod)
1133 {
1134         return 0;
1135 }
1136 #endif /* CONFIG_MODULE_UNLOAD */
1137 
1138 static size_t module_flags_taint(struct module *mod, char *buf)
1139 {
1140         size_t l = 0;
1141 
1142         if (mod->taints & (1 << TAINT_PROPRIETARY_MODULE))
1143                 buf[l++] = 'P';
1144         if (mod->taints & (1 << TAINT_OOT_MODULE))
1145                 buf[l++] = 'O';
1146         if (mod->taints & (1 << TAINT_FORCED_MODULE))
1147                 buf[l++] = 'F';
1148         if (mod->taints & (1 << TAINT_CRAP))
1149                 buf[l++] = 'C';
1150         if (mod->taints & (1 << TAINT_UNSIGNED_MODULE))
1151                 buf[l++] = 'E';
1152         /*
1153          * TAINT_FORCED_RMMOD: could be added.
1154          * TAINT_CPU_OUT_OF_SPEC, TAINT_MACHINE_CHECK, TAINT_BAD_PAGE don't
1155          * apply to modules.
1156          */
1157         return l;
1158 }
1159 
1160 static ssize_t show_initstate(struct module_attribute *mattr,
1161                               struct module_kobject *mk, char *buffer)
1162 {
1163         const char *state = "unknown";
1164 
1165         switch (mk->mod->state) {
1166         case MODULE_STATE_LIVE:
1167                 state = "live";
1168                 break;
1169         case MODULE_STATE_COMING:
1170                 state = "coming";
1171                 break;
1172         case MODULE_STATE_GOING:
1173                 state = "going";
1174                 break;
1175         default:
1176                 BUG();
1177         }
1178         return sprintf(buffer, "%s\n", state);
1179 }
1180 
1181 static struct module_attribute modinfo_initstate =
1182         __ATTR(initstate, 0444, show_initstate, NULL);
1183 
1184 static ssize_t store_uevent(struct module_attribute *mattr,
1185                             struct module_kobject *mk,
1186                             const char *buffer, size_t count)
1187 {
1188         enum kobject_action action;
1189 
1190         if (kobject_action_type(buffer, count, &action) == 0)
1191                 kobject_uevent(&mk->kobj, action);
1192         return count;
1193 }
1194 
1195 struct module_attribute module_uevent =
1196         __ATTR(uevent, 0200, NULL, store_uevent);
1197 
1198 static ssize_t show_coresize(struct module_attribute *mattr,
1199                              struct module_kobject *mk, char *buffer)
1200 {
1201         return sprintf(buffer, "%u\n", mk->mod->core_layout.size);
1202 }
1203 
1204 static struct module_attribute modinfo_coresize =
1205         __ATTR(coresize, 0444, show_coresize, NULL);
1206 
1207 static ssize_t show_initsize(struct module_attribute *mattr,
1208                              struct module_kobject *mk, char *buffer)
1209 {
1210         return sprintf(buffer, "%u\n", mk->mod->init_layout.size);
1211 }
1212 
1213 static struct module_attribute modinfo_initsize =
1214         __ATTR(initsize, 0444, show_initsize, NULL);
1215 
1216 static ssize_t show_taint(struct module_attribute *mattr,
1217                           struct module_kobject *mk, char *buffer)
1218 {
1219         size_t l;
1220 
1221         l = module_flags_taint(mk->mod, buffer);
1222         buffer[l++] = '\n';
1223         return l;
1224 }
1225 
1226 static struct module_attribute modinfo_taint =
1227         __ATTR(taint, 0444, show_taint, NULL);
1228 
1229 static struct module_attribute *modinfo_attrs[] = {
1230         &module_uevent,
1231         &modinfo_version,
1232         &modinfo_srcversion,
1233         &modinfo_initstate,
1234         &modinfo_coresize,
1235         &modinfo_initsize,
1236         &modinfo_taint,
1237 #ifdef CONFIG_MODULE_UNLOAD
1238         &modinfo_refcnt,
1239 #endif
1240         NULL,
1241 };
1242 
1243 static const char vermagic[] = VERMAGIC_STRING;
1244 
1245 static int try_to_force_load(struct module *mod, const char *reason)
1246 {
1247 #ifdef CONFIG_MODULE_FORCE_LOAD
1248         if (!test_taint(TAINT_FORCED_MODULE))
1249                 pr_warn("%s: %s: kernel tainted.\n", mod->name, reason);
1250         add_taint_module(mod, TAINT_FORCED_MODULE, LOCKDEP_NOW_UNRELIABLE);
1251         return 0;
1252 #else
1253         return -ENOEXEC;
1254 #endif
1255 }
1256 
1257 #ifdef CONFIG_MODVERSIONS
1258 /* If the arch applies (non-zero) relocations to kernel kcrctab, unapply it. */
1259 static unsigned long maybe_relocated(unsigned long crc,
1260                                      const struct module *crc_owner)
1261 {
1262 #ifdef ARCH_RELOCATES_KCRCTAB
1263         if (crc_owner == NULL)
1264                 return crc - (unsigned long)reloc_start;
1265 #endif
1266         return crc;
1267 }
1268 
1269 static int check_version(Elf_Shdr *sechdrs,
1270                          unsigned int versindex,
1271                          const char *symname,
1272                          struct module *mod,
1273                          const unsigned long *crc,
1274                          const struct module *crc_owner)
1275 {
1276         unsigned int i, num_versions;
1277         struct modversion_info *versions;
1278 
1279         /* Exporting module didn't supply crcs?  OK, we're already tainted. */
1280         if (!crc)
1281                 return 1;
1282 
1283         /* No versions at all?  modprobe --force does this. */
1284         if (versindex == 0)
1285                 return try_to_force_load(mod, symname) == 0;
1286 
1287         versions = (void *) sechdrs[versindex].sh_addr;
1288         num_versions = sechdrs[versindex].sh_size
1289                 / sizeof(struct modversion_info);
1290 
1291         for (i = 0; i < num_versions; i++) {
1292                 if (strcmp(versions[i].name, symname) != 0)
1293                         continue;
1294 
1295                 if (versions[i].crc == maybe_relocated(*crc, crc_owner))
1296                         return 1;
1297                 pr_debug("Found checksum %lX vs module %lX\n",
1298                        maybe_relocated(*crc, crc_owner), versions[i].crc);
1299                 goto bad_version;
1300         }
1301 
1302         pr_warn("%s: no symbol version for %s\n", mod->name, symname);
1303         return 0;
1304 
1305 bad_version:
1306         pr_warn("%s: disagrees about version of symbol %s\n",
1307                mod->name, symname);
1308         return 0;
1309 }
1310 
1311 static inline int check_modstruct_version(Elf_Shdr *sechdrs,
1312                                           unsigned int versindex,
1313                                           struct module *mod)
1314 {
1315         const unsigned long *crc;
1316 
1317         /*
1318          * Since this should be found in kernel (which can't be removed), no
1319          * locking is necessary -- use preempt_disable() to placate lockdep.
1320          */
1321         preempt_disable();
1322         if (!find_symbol(VMLINUX_SYMBOL_STR(module_layout), NULL,
1323                          &crc, true, false)) {
1324                 preempt_enable();
1325                 BUG();
1326         }
1327         preempt_enable();
1328         return check_version(sechdrs, versindex,
1329                              VMLINUX_SYMBOL_STR(module_layout), mod, crc,
1330                              NULL);
1331 }
1332 
1333 /* First part is kernel version, which we ignore if module has crcs. */
1334 static inline int same_magic(const char *amagic, const char *bmagic,
1335                              bool has_crcs)
1336 {
1337         if (has_crcs) {
1338                 amagic += strcspn(amagic, " ");
1339                 bmagic += strcspn(bmagic, " ");
1340         }
1341         return strcmp(amagic, bmagic) == 0;
1342 }
1343 #else
1344 static inline int check_version(Elf_Shdr *sechdrs,
1345                                 unsigned int versindex,
1346                                 const char *symname,
1347                                 struct module *mod,
1348                                 const unsigned long *crc,
1349                                 const struct module *crc_owner)
1350 {
1351         return 1;
1352 }
1353 
1354 static inline int check_modstruct_version(Elf_Shdr *sechdrs,
1355                                           unsigned int versindex,
1356                                           struct module *mod)
1357 {
1358         return 1;
1359 }
1360 
1361 static inline int same_magic(const char *amagic, const char *bmagic,
1362                              bool has_crcs)
1363 {
1364         return strcmp(amagic, bmagic) == 0;
1365 }
1366 #endif /* CONFIG_MODVERSIONS */
1367 
1368 /* Resolve a symbol for this module.  I.e. if we find one, record usage. */
1369 static const struct kernel_symbol *resolve_symbol(struct module *mod,
1370                                                   const struct load_info *info,
1371                                                   const char *name,
1372                                                   char ownername[])
1373 {
1374         struct module *owner;
1375         const struct kernel_symbol *sym;
1376         const unsigned long *crc;
1377         int err;
1378 
1379         /*
1380          * The module_mutex should not be a heavily contended lock;
1381          * if we get the occasional sleep here, we'll go an extra iteration
1382          * in the wait_event_interruptible(), which is harmless.
1383          */
1384         sched_annotate_sleep();
1385         mutex_lock(&module_mutex);
1386         sym = find_symbol(name, &owner, &crc,
1387                           !(mod->taints & (1 << TAINT_PROPRIETARY_MODULE)), true);
1388         if (!sym)
1389                 goto unlock;
1390 
1391         if (!check_version(info->sechdrs, info->index.vers, name, mod, crc,
1392                            owner)) {
1393                 sym = ERR_PTR(-EINVAL);
1394                 goto getname;
1395         }
1396 
1397         err = ref_module(mod, owner);
1398         if (err) {
1399                 sym = ERR_PTR(err);
1400                 goto getname;
1401         }
1402 
1403 getname:
1404         /* We must make copy under the lock if we failed to get ref. */
1405         strncpy(ownername, module_name(owner), MODULE_NAME_LEN);
1406 unlock:
1407         mutex_unlock(&module_mutex);
1408         return sym;
1409 }
1410 
1411 static const struct kernel_symbol *
1412 resolve_symbol_wait(struct module *mod,
1413                     const struct load_info *info,
1414                     const char *name)
1415 {
1416         const struct kernel_symbol *ksym;
1417         char owner[MODULE_NAME_LEN];
1418 
1419         if (wait_event_interruptible_timeout(module_wq,
1420                         !IS_ERR(ksym = resolve_symbol(mod, info, name, owner))
1421                         || PTR_ERR(ksym) != -EBUSY,
1422                                              30 * HZ) <= 0) {
1423                 pr_warn("%s: gave up waiting for init of module %s.\n",
1424                         mod->name, owner);
1425         }
1426         return ksym;
1427 }
1428 
1429 /*
1430  * /sys/module/foo/sections stuff
1431  * J. Corbet <corbet@lwn.net>
1432  */
1433 #ifdef CONFIG_SYSFS
1434 
1435 #ifdef CONFIG_KALLSYMS
1436 static inline bool sect_empty(const Elf_Shdr *sect)
1437 {
1438         return !(sect->sh_flags & SHF_ALLOC) || sect->sh_size == 0;
1439 }
1440 
1441 struct module_sect_attr {
1442         struct module_attribute mattr;
1443         char *name;
1444         unsigned long address;
1445 };
1446 
1447 struct module_sect_attrs {
1448         struct attribute_group grp;
1449         unsigned int nsections;
1450         struct module_sect_attr attrs[0];
1451 };
1452 
1453 static ssize_t module_sect_show(struct module_attribute *mattr,
1454                                 struct module_kobject *mk, char *buf)
1455 {
1456         struct module_sect_attr *sattr =
1457                 container_of(mattr, struct module_sect_attr, mattr);
1458         return sprintf(buf, "0x%pK\n", (void *)sattr->address);
1459 }
1460 
1461 static void free_sect_attrs(struct module_sect_attrs *sect_attrs)
1462 {
1463         unsigned int section;
1464 
1465         for (section = 0; section < sect_attrs->nsections; section++)
1466                 kfree(sect_attrs->attrs[section].name);
1467         kfree(sect_attrs);
1468 }
1469 
1470 static void add_sect_attrs(struct module *mod, const struct load_info *info)
1471 {
1472         unsigned int nloaded = 0, i, size[2];
1473         struct module_sect_attrs *sect_attrs;
1474         struct module_sect_attr *sattr;
1475         struct attribute **gattr;
1476 
1477         /* Count loaded sections and allocate structures */
1478         for (i = 0; i < info->hdr->e_shnum; i++)
1479                 if (!sect_empty(&info->sechdrs[i]))
1480                         nloaded++;
1481         size[0] = ALIGN(sizeof(*sect_attrs)
1482                         + nloaded * sizeof(sect_attrs->attrs[0]),
1483                         sizeof(sect_attrs->grp.attrs[0]));
1484         size[1] = (nloaded + 1) * sizeof(sect_attrs->grp.attrs[0]);
1485         sect_attrs = kzalloc(size[0] + size[1], GFP_KERNEL);
1486         if (sect_attrs == NULL)
1487                 return;
1488 
1489         /* Setup section attributes. */
1490         sect_attrs->grp.name = "sections";
1491         sect_attrs->grp.attrs = (void *)sect_attrs + size[0];
1492 
1493         sect_attrs->nsections = 0;
1494         sattr = &sect_attrs->attrs[0];
1495         gattr = &sect_attrs->grp.attrs[0];
1496         for (i = 0; i < info->hdr->e_shnum; i++) {
1497                 Elf_Shdr *sec = &info->sechdrs[i];
1498                 if (sect_empty(sec))
1499                         continue;
1500                 sattr->address = sec->sh_addr;
1501                 sattr->name = kstrdup(info->secstrings + sec->sh_name,
1502                                         GFP_KERNEL);
1503                 if (sattr->name == NULL)
1504                         goto out;
1505                 sect_attrs->nsections++;
1506                 sysfs_attr_init(&sattr->mattr.attr);
1507                 sattr->mattr.show = module_sect_show;
1508                 sattr->mattr.store = NULL;
1509                 sattr->mattr.attr.name = sattr->name;
1510                 sattr->mattr.attr.mode = S_IRUGO;
1511                 *(gattr++) = &(sattr++)->mattr.attr;
1512         }
1513         *gattr = NULL;
1514 
1515         if (sysfs_create_group(&mod->mkobj.kobj, &sect_attrs->grp))
1516                 goto out;
1517 
1518         mod->sect_attrs = sect_attrs;
1519         return;
1520   out:
1521         free_sect_attrs(sect_attrs);
1522 }
1523 
1524 static void remove_sect_attrs(struct module *mod)
1525 {
1526         if (mod->sect_attrs) {
1527                 sysfs_remove_group(&mod->mkobj.kobj,
1528                                    &mod->sect_attrs->grp);
1529                 /* We are positive that no one is using any sect attrs
1530                  * at this point.  Deallocate immediately. */
1531                 free_sect_attrs(mod->sect_attrs);
1532                 mod->sect_attrs = NULL;
1533         }
1534 }
1535 
1536 /*
1537  * /sys/module/foo/notes/.section.name gives contents of SHT_NOTE sections.
1538  */
1539 
1540 struct module_notes_attrs {
1541         struct kobject *dir;
1542         unsigned int notes;
1543         struct bin_attribute attrs[0];
1544 };
1545 
1546 static ssize_t module_notes_read(struct file *filp, struct kobject *kobj,
1547                                  struct bin_attribute *bin_attr,
1548                                  char *buf, loff_t pos, size_t count)
1549 {
1550         /*
1551          * The caller checked the pos and count against our size.
1552          */
1553         memcpy(buf, bin_attr->private + pos, count);
1554         return count;
1555 }
1556 
1557 static void free_notes_attrs(struct module_notes_attrs *notes_attrs,
1558                              unsigned int i)
1559 {
1560         if (notes_attrs->dir) {
1561                 while (i-- > 0)
1562                         sysfs_remove_bin_file(notes_attrs->dir,
1563                                               &notes_attrs->attrs[i]);
1564                 kobject_put(notes_attrs->dir);
1565         }
1566         kfree(notes_attrs);
1567 }
1568 
1569 static void add_notes_attrs(struct module *mod, const struct load_info *info)
1570 {
1571         unsigned int notes, loaded, i;
1572         struct module_notes_attrs *notes_attrs;
1573         struct bin_attribute *nattr;
1574 
1575         /* failed to create section attributes, so can't create notes */
1576         if (!mod->sect_attrs)
1577                 return;
1578 
1579         /* Count notes sections and allocate structures.  */
1580         notes = 0;
1581         for (i = 0; i < info->hdr->e_shnum; i++)
1582                 if (!sect_empty(&info->sechdrs[i]) &&
1583                     (info->sechdrs[i].sh_type == SHT_NOTE))
1584                         ++notes;
1585 
1586         if (notes == 0)
1587                 return;
1588 
1589         notes_attrs = kzalloc(sizeof(*notes_attrs)
1590                               + notes * sizeof(notes_attrs->attrs[0]),
1591                               GFP_KERNEL);
1592         if (notes_attrs == NULL)
1593                 return;
1594 
1595         notes_attrs->notes = notes;
1596         nattr = &notes_attrs->attrs[0];
1597         for (loaded = i = 0; i < info->hdr->e_shnum; ++i) {
1598                 if (sect_empty(&info->sechdrs[i]))
1599                         continue;
1600                 if (info->sechdrs[i].sh_type == SHT_NOTE) {
1601                         sysfs_bin_attr_init(nattr);
1602                         nattr->attr.name = mod->sect_attrs->attrs[loaded].name;
1603                         nattr->attr.mode = S_IRUGO;
1604                         nattr->size = info->sechdrs[i].sh_size;
1605                         nattr->private = (void *) info->sechdrs[i].sh_addr;
1606                         nattr->read = module_notes_read;
1607                         ++nattr;
1608                 }
1609                 ++loaded;
1610         }
1611 
1612         notes_attrs->dir = kobject_create_and_add("notes", &mod->mkobj.kobj);
1613         if (!notes_attrs->dir)
1614                 goto out;
1615 
1616         for (i = 0; i < notes; ++i)
1617                 if (sysfs_create_bin_file(notes_attrs->dir,
1618                                           &notes_attrs->attrs[i]))
1619                         goto out;
1620 
1621         mod->notes_attrs = notes_attrs;
1622         return;
1623 
1624   out:
1625         free_notes_attrs(notes_attrs, i);
1626 }
1627 
1628 static void remove_notes_attrs(struct module *mod)
1629 {
1630         if (mod->notes_attrs)
1631                 free_notes_attrs(mod->notes_attrs, mod->notes_attrs->notes);
1632 }
1633 
1634 #else
1635 
1636 static inline void add_sect_attrs(struct module *mod,
1637                                   const struct load_info *info)
1638 {
1639 }
1640 
1641 static inline void remove_sect_attrs(struct module *mod)
1642 {
1643 }
1644 
1645 static inline void add_notes_attrs(struct module *mod,
1646                                    const struct load_info *info)
1647 {
1648 }
1649 
1650 static inline void remove_notes_attrs(struct module *mod)
1651 {
1652 }
1653 #endif /* CONFIG_KALLSYMS */
1654 
1655 static void add_usage_links(struct module *mod)
1656 {
1657 #ifdef CONFIG_MODULE_UNLOAD
1658         struct module_use *use;
1659         int nowarn;
1660 
1661         mutex_lock(&module_mutex);
1662         list_for_each_entry(use, &mod->target_list, target_list) {
1663                 nowarn = sysfs_create_link(use->target->holders_dir,
1664                                            &mod->mkobj.kobj, mod->name);
1665         }
1666         mutex_unlock(&module_mutex);
1667 #endif
1668 }
1669 
1670 static void del_usage_links(struct module *mod)
1671 {
1672 #ifdef CONFIG_MODULE_UNLOAD
1673         struct module_use *use;
1674 
1675         mutex_lock(&module_mutex);
1676         list_for_each_entry(use, &mod->target_list, target_list)
1677                 sysfs_remove_link(use->target->holders_dir, mod->name);
1678         mutex_unlock(&module_mutex);
1679 #endif
1680 }
1681 
1682 static int module_add_modinfo_attrs(struct module *mod)
1683 {
1684         struct module_attribute *attr;
1685         struct module_attribute *temp_attr;
1686         int error = 0;
1687         int i;
1688 
1689         mod->modinfo_attrs = kzalloc((sizeof(struct module_attribute) *
1690                                         (ARRAY_SIZE(modinfo_attrs) + 1)),
1691                                         GFP_KERNEL);
1692         if (!mod->modinfo_attrs)
1693                 return -ENOMEM;
1694 
1695         temp_attr = mod->modinfo_attrs;
1696         for (i = 0; (attr = modinfo_attrs[i]) && !error; i++) {
1697                 if (!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] [ro-after-init] [writable data]
1862  * text_size -----^                ^               ^               ^
1863  * ro_size ------------------------|               |               |
1864  * ro_after_init_size -----------------------------|               |
1865  * size -----------------------------------------------------------|
1866  *
1867  * These values are always page-aligned (as is base)
1868  */
1869 static void frob_text(const struct module_layout *layout,
1870                       int (*set_memory)(unsigned long start, int num_pages))
1871 {
1872         BUG_ON((unsigned long)layout->base & (PAGE_SIZE-1));
1873         BUG_ON((unsigned long)layout->text_size & (PAGE_SIZE-1));
1874         set_memory((unsigned long)layout->base,
1875                    layout->text_size >> PAGE_SHIFT);
1876 }
1877 
1878 static void frob_rodata(const struct module_layout *layout,
1879                         int (*set_memory)(unsigned long start, int num_pages))
1880 {
1881         BUG_ON((unsigned long)layout->base & (PAGE_SIZE-1));
1882         BUG_ON((unsigned long)layout->text_size & (PAGE_SIZE-1));
1883         BUG_ON((unsigned long)layout->ro_size & (PAGE_SIZE-1));
1884         set_memory((unsigned long)layout->base + layout->text_size,
1885                    (layout->ro_size - layout->text_size) >> PAGE_SHIFT);
1886 }
1887 
1888 static void frob_ro_after_init(const struct module_layout *layout,
1889                                 int (*set_memory)(unsigned long start, int num_pages))
1890 {
1891         BUG_ON((unsigned long)layout->base & (PAGE_SIZE-1));
1892         BUG_ON((unsigned long)layout->ro_size & (PAGE_SIZE-1));
1893         BUG_ON((unsigned long)layout->ro_after_init_size & (PAGE_SIZE-1));
1894         set_memory((unsigned long)layout->base + layout->ro_size,
1895                    (layout->ro_after_init_size - layout->ro_size) >> PAGE_SHIFT);
1896 }
1897 
1898 static void frob_writable_data(const struct module_layout *layout,
1899                                int (*set_memory)(unsigned long start, int num_pages))
1900 {
1901         BUG_ON((unsigned long)layout->base & (PAGE_SIZE-1));
1902         BUG_ON((unsigned long)layout->ro_after_init_size & (PAGE_SIZE-1));
1903         BUG_ON((unsigned long)layout->size & (PAGE_SIZE-1));
1904         set_memory((unsigned long)layout->base + layout->ro_after_init_size,
1905                    (layout->size - layout->ro_after_init_size) >> PAGE_SHIFT);
1906 }
1907 
1908 /* livepatching wants to disable read-only so it can frob module. */
1909 void module_disable_ro(const struct module *mod)
1910 {
1911         frob_text(&mod->core_layout, set_memory_rw);
1912         frob_rodata(&mod->core_layout, set_memory_rw);
1913         frob_ro_after_init(&mod->core_layout, set_memory_rw);
1914         frob_text(&mod->init_layout, set_memory_rw);
1915         frob_rodata(&mod->init_layout, set_memory_rw);
1916 }
1917 
1918 void module_enable_ro(const struct module *mod, bool after_init)
1919 {
1920         frob_text(&mod->core_layout, set_memory_ro);
1921         frob_rodata(&mod->core_layout, set_memory_ro);
1922         frob_text(&mod->init_layout, set_memory_ro);
1923         frob_rodata(&mod->init_layout, set_memory_ro);
1924 
1925         if (after_init)
1926                 frob_ro_after_init(&mod->core_layout, set_memory_ro);
1927 }
1928 
1929 static void module_enable_nx(const struct module *mod)
1930 {
1931         frob_rodata(&mod->core_layout, set_memory_nx);
1932         frob_ro_after_init(&mod->core_layout, set_memory_nx);
1933         frob_writable_data(&mod->core_layout, set_memory_nx);
1934         frob_rodata(&mod->init_layout, set_memory_nx);
1935         frob_writable_data(&mod->init_layout, set_memory_nx);
1936 }
1937 
1938 static void module_disable_nx(const struct module *mod)
1939 {
1940         frob_rodata(&mod->core_layout, set_memory_x);
1941         frob_ro_after_init(&mod->core_layout, set_memory_x);
1942         frob_writable_data(&mod->core_layout, set_memory_x);
1943         frob_rodata(&mod->init_layout, set_memory_x);
1944         frob_writable_data(&mod->init_layout, set_memory_x);
1945 }
1946 
1947 /* Iterate through all modules and set each module's text as RW */
1948 void set_all_modules_text_rw(void)
1949 {
1950         struct module *mod;
1951 
1952         mutex_lock(&module_mutex);
1953         list_for_each_entry_rcu(mod, &modules, list) {
1954                 if (mod->state == MODULE_STATE_UNFORMED)
1955                         continue;
1956 
1957                 frob_text(&mod->core_layout, set_memory_rw);
1958                 frob_text(&mod->init_layout, set_memory_rw);
1959         }
1960         mutex_unlock(&module_mutex);
1961 }
1962 
1963 /* Iterate through all modules and set each module's text as RO */
1964 void set_all_modules_text_ro(void)
1965 {
1966         struct module *mod;
1967 
1968         mutex_lock(&module_mutex);
1969         list_for_each_entry_rcu(mod, &modules, list) {
1970                 if (mod->state == MODULE_STATE_UNFORMED)
1971                         continue;
1972 
1973                 frob_text(&mod->core_layout, set_memory_ro);
1974                 frob_text(&mod->init_layout, set_memory_ro);
1975         }
1976         mutex_unlock(&module_mutex);
1977 }
1978 
1979 static void disable_ro_nx(const struct module_layout *layout)
1980 {
1981         frob_text(layout, set_memory_rw);
1982         frob_rodata(layout, set_memory_rw);
1983         frob_rodata(layout, set_memory_x);
1984         frob_ro_after_init(layout, set_memory_rw);
1985         frob_ro_after_init(layout, set_memory_x);
1986         frob_writable_data(layout, set_memory_x);
1987 }
1988 
1989 #else
1990 static void disable_ro_nx(const struct module_layout *layout) { }
1991 static void module_enable_nx(const struct module *mod) { }
1992 static void module_disable_nx(const struct module *mod) { }
1993 #endif
1994 
1995 #ifdef CONFIG_LIVEPATCH
1996 /*
1997  * Persist Elf information about a module. Copy the Elf header,
1998  * section header table, section string table, and symtab section
1999  * index from info to mod->klp_info.
2000  */
2001 static int copy_module_elf(struct module *mod, struct load_info *info)
2002 {
2003         unsigned int size, symndx;
2004         int ret;
2005 
2006         size = sizeof(*mod->klp_info);
2007         mod->klp_info = kmalloc(size, GFP_KERNEL);
2008         if (mod->klp_info == NULL)
2009                 return -ENOMEM;
2010 
2011         /* Elf header */
2012         size = sizeof(mod->klp_info->hdr);
2013         memcpy(&mod->klp_info->hdr, info->hdr, size);
2014 
2015         /* Elf section header table */
2016         size = sizeof(*info->sechdrs) * info->hdr->e_shnum;
2017         mod->klp_info->sechdrs = kmalloc(size, GFP_KERNEL);
2018         if (mod->klp_info->sechdrs == NULL) {
2019                 ret = -ENOMEM;
2020                 goto free_info;
2021         }
2022         memcpy(mod->klp_info->sechdrs, info->sechdrs, size);
2023 
2024         /* Elf section name string table */
2025         size = info->sechdrs[info->hdr->e_shstrndx].sh_size;
2026         mod->klp_info->secstrings = kmalloc(size, GFP_KERNEL);
2027         if (mod->klp_info->secstrings == NULL) {
2028                 ret = -ENOMEM;
2029                 goto free_sechdrs;
2030         }
2031         memcpy(mod->klp_info->secstrings, info->secstrings, size);
2032 
2033         /* Elf symbol section index */
2034         symndx = info->index.sym;
2035         mod->klp_info->symndx = symndx;
2036 
2037         /*
2038          * For livepatch modules, core_kallsyms.symtab is a complete
2039          * copy of the original symbol table. Adjust sh_addr to point
2040          * to core_kallsyms.symtab since the copy of the symtab in module
2041          * init memory is freed at the end of do_init_module().
2042          */
2043         mod->klp_info->sechdrs[symndx].sh_addr = \
2044                 (unsigned long) mod->core_kallsyms.symtab;
2045 
2046         return 0;
2047 
2048 free_sechdrs:
2049         kfree(mod->klp_info->sechdrs);
2050 free_info:
2051         kfree(mod->klp_info);
2052         return ret;
2053 }
2054 
2055 static void free_module_elf(struct module *mod)
2056 {
2057         kfree(mod->klp_info->sechdrs);
2058         kfree(mod->klp_info->secstrings);
2059         kfree(mod->klp_info);
2060 }
2061 #else /* !CONFIG_LIVEPATCH */
2062 static int copy_module_elf(struct module *mod, struct load_info *info)
2063 {
2064         return 0;
2065 }
2066 
2067 static void free_module_elf(struct module *mod)
2068 {
2069 }
2070 #endif /* CONFIG_LIVEPATCH */
2071 
2072 void __weak module_memfree(void *module_region)
2073 {
2074         vfree(module_region);
2075 }
2076 
2077 void __weak module_arch_cleanup(struct module *mod)
2078 {
2079 }
2080 
2081 void __weak module_arch_freeing_init(struct module *mod)
2082 {
2083 }
2084 
2085 /* Free a module, remove from lists, etc. */
2086 static void free_module(struct module *mod)
2087 {
2088         trace_module_free(mod);
2089 
2090         mod_sysfs_teardown(mod);
2091 
2092         /* We leave it in list to prevent duplicate loads, but make sure
2093          * that noone uses it while it's being deconstructed. */
2094         mutex_lock(&module_mutex);
2095         mod->state = MODULE_STATE_UNFORMED;
2096         mutex_unlock(&module_mutex);
2097 
2098         /* Remove dynamic debug info */
2099         ddebug_remove_module(mod->name);
2100 
2101         /* Arch-specific cleanup. */
2102         module_arch_cleanup(mod);
2103 
2104         /* Module unload stuff */
2105         module_unload_free(mod);
2106 
2107         /* Free any allocated parameters. */
2108         destroy_params(mod->kp, mod->num_kp);
2109 
2110         if (is_livepatch_module(mod))
2111                 free_module_elf(mod);
2112 
2113         /* Now we can delete it from the lists */
2114         mutex_lock(&module_mutex);
2115         /* Unlink carefully: kallsyms could be walking list. */
2116         list_del_rcu(&mod->list);
2117         mod_tree_remove(mod);
2118         /* Remove this module from bug list, this uses list_del_rcu */
2119         module_bug_cleanup(mod);
2120         /* Wait for RCU-sched synchronizing before releasing mod->list and buglist. */
2121         synchronize_sched();
2122         mutex_unlock(&module_mutex);
2123 
2124         /* This may be empty, but that's OK */
2125         disable_ro_nx(&mod->init_layout);
2126         module_arch_freeing_init(mod);
2127         module_memfree(mod->init_layout.base);
2128         kfree(mod->args);
2129         percpu_modfree(mod);
2130 
2131         /* Free lock-classes; relies on the preceding sync_rcu(). */
2132         lockdep_free_key_range(mod->core_layout.base, mod->core_layout.size);
2133 
2134         /* Finally, free the core (containing the module structure) */
2135         disable_ro_nx(&mod->core_layout);
2136         module_memfree(mod->core_layout.base);
2137 
2138 #ifdef CONFIG_MPU
2139         update_protections(current->mm);
2140 #endif
2141 }
2142 
2143 void *__symbol_get(const char *symbol)
2144 {
2145         struct module *owner;
2146         const struct kernel_symbol *sym;
2147 
2148         preempt_disable();
2149         sym = find_symbol(symbol, &owner, NULL, true, true);
2150         if (sym && strong_try_module_get(owner))
2151                 sym = NULL;
2152         preempt_enable();
2153 
2154         return sym ? (void *)sym->value : NULL;
2155 }
2156 EXPORT_SYMBOL_GPL(__symbol_get);
2157 
2158 /*
2159  * Ensure that an exported symbol [global namespace] does not already exist
2160  * in the kernel or in some other module's exported symbol table.
2161  *
2162  * You must hold the module_mutex.
2163  */
2164 static int verify_export_symbols(struct module *mod)
2165 {
2166         unsigned int i;
2167         struct module *owner;
2168         const struct kernel_symbol *s;
2169         struct {
2170                 const struct kernel_symbol *sym;
2171                 unsigned int num;
2172         } arr[] = {
2173                 { mod->syms, mod->num_syms },
2174                 { mod->gpl_syms, mod->num_gpl_syms },
2175                 { mod->gpl_future_syms, mod->num_gpl_future_syms },
2176 #ifdef CONFIG_UNUSED_SYMBOLS
2177                 { mod->unused_syms, mod->num_unused_syms },
2178                 { mod->unused_gpl_syms, mod->num_unused_gpl_syms },
2179 #endif
2180         };
2181 
2182         for (i = 0; i < ARRAY_SIZE(arr); i++) {
2183                 for (s = arr[i].sym; s < arr[i].sym + arr[i].num; s++) {
2184                         if (find_symbol(s->name, &owner, NULL, true, false)) {
2185                                 pr_err("%s: exports duplicate symbol %s"
2186                                        " (owned by %s)\n",
2187                                        mod->name, s->name, module_name(owner));
2188                                 return -ENOEXEC;
2189                         }
2190                 }
2191         }
2192         return 0;
2193 }
2194 
2195 /* Change all symbols so that st_value encodes the pointer directly. */
2196 static int simplify_symbols(struct module *mod, const struct load_info *info)
2197 {
2198         Elf_Shdr *symsec = &info->sechdrs[info->index.sym];
2199         Elf_Sym *sym = (void *)symsec->sh_addr;
2200         unsigned long secbase;
2201         unsigned int i;
2202         int ret = 0;
2203         const struct kernel_symbol *ksym;
2204 
2205         for (i = 1; i < symsec->sh_size / sizeof(Elf_Sym); i++) {
2206                 const char *name = info->strtab + sym[i].st_name;
2207 
2208                 switch (sym[i].st_shndx) {
2209                 case SHN_COMMON:
2210                         /* Ignore common symbols */
2211                         if (!strncmp(name, "__gnu_lto", 9))
2212                                 break;
2213 
2214                         /* We compiled with -fno-common.  These are not
2215                            supposed to happen.  */
2216                         pr_debug("Common symbol: %s\n", name);
2217                         pr_warn("%s: please compile with -fno-common\n",
2218                                mod->name);
2219                         ret = -ENOEXEC;
2220                         break;
2221 
2222                 case SHN_ABS:
2223                         /* Don't need to do anything */
2224                         pr_debug("Absolute symbol: 0x%08lx\n",
2225                                (long)sym[i].st_value);
2226                         break;
2227 
2228                 case SHN_LIVEPATCH:
2229                         /* Livepatch symbols are resolved by livepatch */
2230                         break;
2231 
2232                 case SHN_UNDEF:
2233                         ksym = resolve_symbol_wait(mod, info, name);
2234                         /* Ok if resolved.  */
2235                         if (ksym && !IS_ERR(ksym)) {
2236                                 sym[i].st_value = ksym->value;
2237                                 break;
2238                         }
2239 
2240                         /* Ok if weak.  */
2241                         if (!ksym && ELF_ST_BIND(sym[i].st_info) == STB_WEAK)
2242                                 break;
2243 
2244                         pr_warn("%s: Unknown symbol %s (err %li)\n",
2245                                 mod->name, name, PTR_ERR(ksym));
2246                         ret = PTR_ERR(ksym) ?: -ENOENT;
2247                         break;
2248 
2249                 default:
2250                         /* Divert to percpu allocation if a percpu var. */
2251                         if (sym[i].st_shndx == info->index.pcpu)
2252                                 secbase = (unsigned long)mod_percpu(mod);
2253                         else
2254                                 secbase = info->sechdrs[sym[i].st_shndx].sh_addr;
2255                         sym[i].st_value += secbase;
2256                         break;
2257                 }
2258         }
2259 
2260         return ret;
2261 }
2262 
2263 static int apply_relocations(struct module *mod, const struct load_info *info)
2264 {
2265         unsigned int i;
2266         int err = 0;
2267 
2268         /* Now do relocations. */
2269         for (i = 1; i < info->hdr->e_shnum; i++) {
2270                 unsigned int infosec = info->sechdrs[i].sh_info;
2271 
2272                 /* Not a valid relocation section? */
2273                 if (infosec >= info->hdr->e_shnum)
2274                         continue;
2275 
2276                 /* Don't bother with non-allocated sections */
2277                 if (!(info->sechdrs[infosec].sh_flags & SHF_ALLOC))
2278                         continue;
2279 
2280                 /* Livepatch relocation sections are applied by livepatch */
2281                 if (info->sechdrs[i].sh_flags & SHF_RELA_LIVEPATCH)
2282                         continue;
2283 
2284                 if (info->sechdrs[i].sh_type == SHT_REL)
2285                         err = apply_relocate(info->sechdrs, info->strtab,
2286                                              info->index.sym, i, mod);
2287                 else if (info->sechdrs[i].sh_type == SHT_RELA)
2288                         err = apply_relocate_add(info->sechdrs, info->strtab,
2289                                                  info->index.sym, i, mod);
2290                 if (err < 0)
2291                         break;
2292         }
2293         return err;
2294 }
2295 
2296 /* Additional bytes needed by arch in front of individual sections */
2297 unsigned int __weak arch_mod_section_prepend(struct module *mod,
2298                                              unsigned int section)
2299 {
2300         /* default implementation just returns zero */
2301         return 0;
2302 }
2303 
2304 /* Update size with this section: return offset. */
2305 static long get_offset(struct module *mod, unsigned int *size,
2306                        Elf_Shdr *sechdr, unsigned int section)
2307 {
2308         long ret;
2309 
2310         *size += arch_mod_section_prepend(mod, section);
2311         ret = ALIGN(*size, sechdr->sh_addralign ?: 1);
2312         *size = ret + sechdr->sh_size;
2313         return ret;
2314 }
2315 
2316 /* Lay out the SHF_ALLOC sections in a way not dissimilar to how ld
2317    might -- code, read-only data, read-write data, small data.  Tally
2318    sizes, and place the offsets into sh_entsize fields: high bit means it
2319    belongs in init. */
2320 static void layout_sections(struct module *mod, struct load_info *info)
2321 {
2322         static unsigned long const masks[][2] = {
2323                 /* NOTE: all executable code must be the first section
2324                  * in this array; otherwise modify the text_size
2325                  * finder in the two loops below */
2326                 { SHF_EXECINSTR | SHF_ALLOC, ARCH_SHF_SMALL },
2327                 { SHF_ALLOC, SHF_WRITE | ARCH_SHF_SMALL },
2328                 { SHF_RO_AFTER_INIT | SHF_ALLOC, ARCH_SHF_SMALL },
2329                 { SHF_WRITE | SHF_ALLOC, ARCH_SHF_SMALL },
2330                 { ARCH_SHF_SMALL | SHF_ALLOC, 0 }
2331         };
2332         unsigned int m, i;
2333 
2334         for (i = 0; i < info->hdr->e_shnum; i++)
2335                 info->sechdrs[i].sh_entsize = ~0UL;
2336 
2337         pr_debug("Core section allocation order:\n");
2338         for (m = 0; m < ARRAY_SIZE(masks); ++m) {
2339                 for (i = 0; i < info->hdr->e_shnum; ++i) {
2340                         Elf_Shdr *s = &info->sechdrs[i];
2341                         const char *sname = info->secstrings + s->sh_name;
2342 
2343                         if ((s->sh_flags & masks[m][0]) != masks[m][0]
2344                             || (s->sh_flags & masks[m][1])
2345                             || s->sh_entsize != ~0UL
2346                             || strstarts(sname, ".init"))
2347                                 continue;
2348                         s->sh_entsize = get_offset(mod, &mod->core_layout.size, s, i);
2349                         pr_debug("\t%s\n", sname);
2350                 }
2351                 switch (m) {
2352                 case 0: /* executable */
2353                         mod->core_layout.size = debug_align(mod->core_layout.size);
2354                         mod->core_layout.text_size = mod->core_layout.size;
2355                         break;
2356                 case 1: /* RO: text and ro-data */
2357                         mod->core_layout.size = debug_align(mod->core_layout.size);
2358                         mod->core_layout.ro_size = mod->core_layout.size;
2359                         break;
2360                 case 2: /* RO after init */
2361                         mod->core_layout.size = debug_align(mod->core_layout.size);
2362                         mod->core_layout.ro_after_init_size = mod->core_layout.size;
2363                         break;
2364                 case 4: /* whole core */
2365                         mod->core_layout.size = debug_align(mod->core_layout.size);
2366                         break;
2367                 }
2368         }
2369 
2370         pr_debug("Init section allocation order:\n");
2371         for (m = 0; m < ARRAY_SIZE(masks); ++m) {
2372                 for (i = 0; i < info->hdr->e_shnum; ++i) {
2373                         Elf_Shdr *s = &info->sechdrs[i];
2374                         const char *sname = info->secstrings + s->sh_name;
2375 
2376                         if ((s->sh_flags & masks[m][0]) != masks[m][0]
2377                             || (s->sh_flags & masks[m][1])
2378                             || s->sh_entsize != ~0UL
2379                             || !strstarts(sname, ".init"))
2380                                 continue;
2381                         s->sh_entsize = (get_offset(mod, &mod->init_layout.size, s, i)
2382                                          | INIT_OFFSET_MASK);
2383                         pr_debug("\t%s\n", sname);
2384                 }
2385                 switch (m) {
2386                 case 0: /* executable */
2387                         mod->init_layout.size = debug_align(mod->init_layout.size);
2388                         mod->init_layout.text_size = mod->init_layout.size;
2389                         break;
2390                 case 1: /* RO: text and ro-data */
2391                         mod->init_layout.size = debug_align(mod->init_layout.size);
2392                         mod->init_layout.ro_size = mod->init_layout.size;
2393                         break;
2394                 case 2:
2395                         /*
2396                          * RO after init doesn't apply to init_layout (only
2397                          * core_layout), so it just takes the value of ro_size.
2398                          */
2399                         mod->init_layout.ro_after_init_size = mod->init_layout.ro_size;
2400                         break;
2401                 case 4: /* whole init */
2402                         mod->init_layout.size = debug_align(mod->init_layout.size);
2403                         break;
2404                 }
2405         }
2406 }
2407 
2408 static void set_license(struct module *mod, const char *license)
2409 {
2410         if (!license)
2411                 license = "unspecified";
2412 
2413         if (!license_is_gpl_compatible(license)) {
2414                 if (!test_taint(TAINT_PROPRIETARY_MODULE))
2415                         pr_warn("%s: module license '%s' taints kernel.\n",
2416                                 mod->name, license);
2417                 add_taint_module(mod, TAINT_PROPRIETARY_MODULE,
2418                                  LOCKDEP_NOW_UNRELIABLE);
2419         }
2420 }
2421 
2422 /* Parse tag=value strings from .modinfo section */
2423 static char *next_string(char *string, unsigned long *secsize)
2424 {
2425         /* Skip non-zero chars */
2426         while (string[0]) {
2427                 string++;
2428                 if ((*secsize)-- <= 1)
2429                         return NULL;
2430         }
2431 
2432         /* Skip any zero padding. */
2433         while (!string[0]) {
2434                 string++;
2435                 if ((*secsize)-- <= 1)
2436                         return NULL;
2437         }
2438         return string;
2439 }
2440 
2441 static char *get_modinfo(struct load_info *info, const char *tag)
2442 {
2443         char *p;
2444         unsigned int taglen = strlen(tag);
2445         Elf_Shdr *infosec = &info->sechdrs[info->index.info];
2446         unsigned long size = infosec->sh_size;
2447 
2448         for (p = (char *)infosec->sh_addr; p; p = next_string(p, &size)) {
2449                 if (strncmp(p, tag, taglen) == 0 && p[taglen] == '=')
2450                         return p + taglen + 1;
2451         }
2452         return NULL;
2453 }
2454 
2455 static void setup_modinfo(struct module *mod, struct load_info *info)
2456 {
2457         struct module_attribute *attr;
2458         int i;
2459 
2460         for (i = 0; (attr = modinfo_attrs[i]); i++) {
2461                 if (attr->setup)
2462                         attr->setup(mod, get_modinfo(info, attr->attr.name));
2463         }
2464 }
2465 
2466 static void free_modinfo(struct module *mod)
2467 {
2468         struct module_attribute *attr;
2469         int i;
2470 
2471         for (i = 0; (attr = modinfo_attrs[i]); i++) {
2472                 if (attr->free)
2473                         attr->free(mod);
2474         }
2475 }
2476 
2477 #ifdef CONFIG_KALLSYMS
2478 
2479 /* lookup symbol in given range of kernel_symbols */
2480 static const struct kernel_symbol *lookup_symbol(const char *name,
2481         const struct kernel_symbol *start,
2482         const struct kernel_symbol *stop)
2483 {
2484         return bsearch(name, start, stop - start,
2485                         sizeof(struct kernel_symbol), cmp_name);
2486 }
2487 
2488 static int is_exported(const char *name, unsigned long value,
2489                        const struct module *mod)
2490 {
2491         const struct kernel_symbol *ks;
2492         if (!mod)
2493                 ks = lookup_symbol(name, __start___ksymtab, __stop___ksymtab);
2494         else
2495                 ks = lookup_symbol(name, mod->syms, mod->syms + mod->num_syms);
2496         return ks != NULL && ks->value == value;
2497 }
2498 
2499 /* As per nm */
2500 static char elf_type(const Elf_Sym *sym, const struct load_info *info)
2501 {
2502         const Elf_Shdr *sechdrs = info->sechdrs;
2503 
2504         if (ELF_ST_BIND(sym->st_info) == STB_WEAK) {
2505                 if (ELF_ST_TYPE(sym->st_info) == STT_OBJECT)
2506                         return 'v';
2507                 else
2508                         return 'w';
2509         }
2510         if (sym->st_shndx == SHN_UNDEF)
2511                 return 'U';
2512         if (sym->st_shndx == SHN_ABS || sym->st_shndx == info->index.pcpu)
2513                 return 'a';
2514         if (sym->st_shndx >= SHN_LORESERVE)
2515                 return '?';
2516         if (sechdrs[sym->st_shndx].sh_flags & SHF_EXECINSTR)
2517                 return 't';
2518         if (sechdrs[sym->st_shndx].sh_flags & SHF_ALLOC
2519             && sechdrs[sym->st_shndx].sh_type != SHT_NOBITS) {
2520                 if (!(sechdrs[sym->st_shndx].sh_flags & SHF_WRITE))
2521                         return 'r';
2522                 else if (sechdrs[sym->st_shndx].sh_flags & ARCH_SHF_SMALL)
2523                         return 'g';
2524                 else
2525                         return 'd';
2526         }
2527         if (sechdrs[sym->st_shndx].sh_type == SHT_NOBITS) {
2528                 if (sechdrs[sym->st_shndx].sh_flags & ARCH_SHF_SMALL)
2529                         return 's';
2530                 else
2531                         return 'b';
2532         }
2533         if (strstarts(info->secstrings + sechdrs[sym->st_shndx].sh_name,
2534                       ".debug")) {
2535                 return 'n';
2536         }
2537         return '?';
2538 }
2539 
2540 static bool is_core_symbol(const Elf_Sym *src, const Elf_Shdr *sechdrs,
2541                         unsigned int shnum, unsigned int pcpundx)
2542 {
2543         const Elf_Shdr *sec;
2544 
2545         if (src->st_shndx == SHN_UNDEF
2546             || src->st_shndx >= shnum
2547             || !src->st_name)
2548                 return false;
2549 
2550 #ifdef CONFIG_KALLSYMS_ALL
2551         if (src->st_shndx == pcpundx)
2552                 return true;
2553 #endif
2554 
2555         sec = sechdrs + src->st_shndx;
2556         if (!(sec->sh_flags & SHF_ALLOC)
2557 #ifndef CONFIG_KALLSYMS_ALL
2558             || !(sec->sh_flags & SHF_EXECINSTR)
2559 #endif
2560             || (sec->sh_entsize & INIT_OFFSET_MASK))
2561                 return false;
2562 
2563         return true;
2564 }
2565 
2566 /*
2567  * We only allocate and copy the strings needed by the parts of symtab
2568  * we keep.  This is simple, but has the effect of making multiple
2569  * copies of duplicates.  We could be more sophisticated, see
2570  * linux-kernel thread starting with
2571  * <73defb5e4bca04a6431392cc341112b1@localhost>.
2572  */
2573 static void layout_symtab(struct module *mod, struct load_info *info)
2574 {
2575         Elf_Shdr *symsect = info->sechdrs + info->index.sym;
2576         Elf_Shdr *strsect = info->sechdrs + info->index.str;
2577         const Elf_Sym *src;
2578         unsigned int i, nsrc, ndst, strtab_size = 0;
2579 
2580         /* Put symbol section at end of init part of module. */
2581         symsect->sh_flags |= SHF_ALLOC;
2582         symsect->sh_entsize = get_offset(mod, &mod->init_layout.size, symsect,
2583                                          info->index.sym) | INIT_OFFSET_MASK;
2584         pr_debug("\t%s\n", info->secstrings + symsect->sh_name);
2585 
2586         src = (void *)info->hdr + symsect->sh_offset;
2587         nsrc = symsect->sh_size / sizeof(*src);
2588 
2589         /* Compute total space required for the core symbols' strtab. */
2590         for (ndst = i = 0; i < nsrc; i++) {
2591                 if (i == 0 || is_livepatch_module(mod) ||
2592                     is_core_symbol(src+i, info->sechdrs, info->hdr->e_shnum,
2593                                    info->index.pcpu)) {
2594                         strtab_size += strlen(&info->strtab[src[i].st_name])+1;
2595                         ndst++;
2596                 }
2597         }
2598 
2599         /* Append room for core symbols at end of core part. */
2600         info->symoffs = ALIGN(mod->core_layout.size, symsect->sh_addralign ?: 1);
2601         info->stroffs = mod->core_layout.size = info->symoffs + ndst * sizeof(Elf_Sym);
2602         mod->core_layout.size += strtab_size;
2603         mod->core_layout.size = debug_align(mod->core_layout.size);
2604 
2605         /* Put string table section at end of init part of module. */
2606         strsect->sh_flags |= SHF_ALLOC;
2607         strsect->sh_entsize = get_offset(mod, &mod->init_layout.size, strsect,
2608                                          info->index.str) | INIT_OFFSET_MASK;
2609         pr_debug("\t%s\n", info->secstrings + strsect->sh_name);
2610 
2611         /* We'll tack temporary mod_kallsyms on the end. */
2612         mod->init_layout.size = ALIGN(mod->init_layout.size,
2613                                       __alignof__(struct mod_kallsyms));
2614         info->mod_kallsyms_init_off = mod->init_layout.size;
2615         mod->init_layout.size += sizeof(struct mod_kallsyms);
2616         mod->init_layout.size = debug_align(mod->init_layout.size);
2617 }
2618 
2619 /*
2620  * We use the full symtab and strtab which layout_symtab arranged to
2621  * be appended to the init section.  Later we switch to the cut-down
2622  * core-only ones.
2623  */
2624 static void add_kallsyms(struct module *mod, const struct load_info *info)
2625 {
2626         unsigned int i, ndst;
2627         const Elf_Sym *src;
2628         Elf_Sym *dst;
2629         char *s;
2630         Elf_Shdr *symsec = &info->sechdrs[info->index.sym];
2631 
2632         /* Set up to point into init section. */
2633         mod->kallsyms = mod->init_layout.base + info->mod_kallsyms_init_off;
2634 
2635         mod->kallsyms->symtab = (void *)symsec->sh_addr;
2636         mod->kallsyms->num_symtab = symsec->sh_size / sizeof(Elf_Sym);
2637         /* Make sure we get permanent strtab: don't use info->strtab. */
2638         mod->kallsyms->strtab = (void *)info->sechdrs[info->index.str].sh_addr;
2639 
2640         /* Set types up while we still have access to sections. */
2641         for (i = 0; i < mod->kallsyms->num_symtab; i++)
2642                 mod->kallsyms->symtab[i].st_info
2643                         = elf_type(&mod->kallsyms->symtab[i], info);
2644 
2645         /* Now populate the cut down core kallsyms for after init. */
2646         mod->core_kallsyms.symtab = dst = mod->core_layout.base + info->symoffs;
2647         mod->core_kallsyms.strtab = s = mod->core_layout.base + info->stroffs;
2648         src = mod->kallsyms->symtab;
2649         for (ndst = i = 0; i < mod->kallsyms->num_symtab; i++) {
2650                 if (i == 0 || is_livepatch_module(mod) ||
2651                     is_core_symbol(src+i, info->sechdrs, info->hdr->e_shnum,
2652                                    info->index.pcpu)) {
2653                         dst[ndst] = src[i];
2654                         dst[ndst++].st_name = s - mod->core_kallsyms.strtab;
2655                         s += strlcpy(s, &mod->kallsyms->strtab[src[i].st_name],
2656                                      KSYM_NAME_LEN) + 1;
2657                 }
2658         }
2659         mod->core_kallsyms.num_symtab = ndst;
2660 }
2661 #else
2662 static inline void layout_symtab(struct module *mod, struct load_info *info)
2663 {
2664 }
2665 
2666 static void add_kallsyms(struct module *mod, const struct load_info *info)
2667 {
2668 }
2669 #endif /* CONFIG_KALLSYMS */
2670 
2671 static void dynamic_debug_setup(struct _ddebug *debug, unsigned int num)
2672 {
2673         if (!debug)
2674                 return;
2675 #ifdef CONFIG_DYNAMIC_DEBUG
2676         if (ddebug_add_module(debug, num, debug->modname))
2677                 pr_err("dynamic debug error adding module: %s\n",
2678                         debug->modname);
2679 #endif
2680 }
2681 
2682 static void dynamic_debug_remove(struct _ddebug *debug)
2683 {
2684         if (debug)
2685                 ddebug_remove_module(debug->modname);
2686 }
2687 
2688 void * __weak module_alloc(unsigned long size)
2689 {
2690         return vmalloc_exec(size);
2691 }
2692 
2693 #ifdef CONFIG_DEBUG_KMEMLEAK
2694 static void kmemleak_load_module(const struct module *mod,
2695                                  const struct load_info *info)
2696 {
2697         unsigned int i;
2698 
2699         /* only scan the sections containing data */
2700         kmemleak_scan_area(mod, sizeof(struct module), GFP_KERNEL);
2701 
2702         for (i = 1; i < info->hdr->e_shnum; i++) {
2703                 /* Scan all writable sections that's not executable */
2704                 if (!(info->sechdrs[i].sh_flags & SHF_ALLOC) ||
2705                     !(info->sechdrs[i].sh_flags & SHF_WRITE) ||
2706                     (info->sechdrs[i].sh_flags & SHF_EXECINSTR))
2707                         continue;
2708 
2709                 kmemleak_scan_area((void *)info->sechdrs[i].sh_addr,
2710                                    info->sechdrs[i].sh_size, GFP_KERNEL);
2711         }
2712 }
2713 #else
2714 static inline void kmemleak_load_module(const struct module *mod,
2715                                         const struct load_info *info)
2716 {
2717 }
2718 #endif
2719 
2720 #ifdef CONFIG_MODULE_SIG
2721 static int module_sig_check(struct load_info *info, int flags)
2722 {
2723         int err = -ENOKEY;
2724         const unsigned long markerlen = sizeof(MODULE_SIG_STRING) - 1;
2725         const void *mod = info->hdr;
2726 
2727         /*
2728          * Require flags == 0, as a module with version information
2729          * removed is no longer the module that was signed
2730          */
2731         if (flags == 0 &&
2732             info->len > markerlen &&
2733             memcmp(mod + info->len - markerlen, MODULE_SIG_STRING, markerlen) == 0) {
2734                 /* We truncate the module to discard the signature */
2735                 info->len -= markerlen;
2736                 err = mod_verify_sig(mod, &info->len);
2737         }
2738 
2739         if (!err) {
2740                 info->sig_ok = true;
2741                 return 0;
2742         }
2743 
2744         /* Not having a signature is only an error if we're strict. */
2745         if (err == -ENOKEY && !sig_enforce)
2746                 err = 0;
2747 
2748         return err;
2749 }
2750 #else /* !CONFIG_MODULE_SIG */
2751 static int module_sig_check(struct load_info *info, int flags)
2752 {
2753         return 0;
2754 }
2755 #endif /* !CONFIG_MODULE_SIG */
2756 
2757 /* Sanity checks against invalid binaries, wrong arch, weird elf version. */
2758 static int elf_header_check(struct load_info *info)
2759 {
2760         if (info->len < sizeof(*(info->hdr)))
2761                 return -ENOEXEC;
2762 
2763         if (memcmp(info->hdr->e_ident, ELFMAG, SELFMAG) != 0
2764             || info->hdr->e_type != ET_REL
2765             || !elf_check_arch(info->hdr)
2766             || info->hdr->e_shentsize != sizeof(Elf_Shdr))
2767                 return -ENOEXEC;
2768 
2769         if (info->hdr->e_shoff >= info->len
2770             || (info->hdr->e_shnum * sizeof(Elf_Shdr) >
2771                 info->len - info->hdr->e_shoff))
2772                 return -ENOEXEC;
2773 
2774         return 0;
2775 }
2776 
2777 #define COPY_CHUNK_SIZE (16*PAGE_SIZE)
2778 
2779 static int copy_chunked_from_user(void *dst, const void __user *usrc, unsigned long len)
2780 {
2781         do {
2782                 unsigned long n = min(len, COPY_CHUNK_SIZE);
2783 
2784                 if (copy_from_user(dst, usrc, n) != 0)
2785                         return -EFAULT;
2786                 cond_resched();
2787                 dst += n;
2788                 usrc += n;
2789                 len -= n;
2790         } while (len);
2791         return 0;
2792 }
2793 
2794 #ifdef CONFIG_LIVEPATCH
2795 static int find_livepatch_modinfo(struct module *mod, struct load_info *info)
2796 {
2797         mod->klp = get_modinfo(info, "livepatch") ? true : false;
2798 
2799         return 0;
2800 }
2801 #else /* !CONFIG_LIVEPATCH */
2802 static int find_livepatch_modinfo(struct module *mod, struct load_info *info)
2803 {
2804         if (get_modinfo(info, "livepatch")) {
2805                 pr_err("%s: module is marked as livepatch module, but livepatch support is disabled",
2806                        mod->name);
2807                 return -ENOEXEC;
2808         }
2809 
2810         return 0;
2811 }
2812 #endif /* CONFIG_LIVEPATCH */
2813 
2814 /* Sets info->hdr and info->len. */
2815 static int copy_module_from_user(const void __user *umod, unsigned long len,
2816                                   struct load_info *info)
2817 {
2818         int err;
2819 
2820         info->len = len;
2821         if (info->len < sizeof(*(info->hdr)))
2822                 return -ENOEXEC;
2823 
2824         err = security_kernel_read_file(NULL, READING_MODULE);
2825         if (err)
2826                 return err;
2827 
2828         /* Suck in entire file: we'll want most of it. */
2829         info->hdr = __vmalloc(info->len,
2830                         GFP_KERNEL | __GFP_HIGHMEM | __GFP_NOWARN, PAGE_KERNEL);
2831         if (!info->hdr)
2832                 return -ENOMEM;
2833 
2834         if (copy_chunked_from_user(info->hdr, umod, info->len) != 0) {
2835                 vfree(info->hdr);
2836                 return -EFAULT;
2837         }
2838 
2839         return 0;
2840 }
2841 
2842 static void free_copy(struct load_info *info)
2843 {
2844         vfree(info->hdr);
2845 }
2846 
2847 static int rewrite_section_headers(struct load_info *info, int flags)
2848 {
2849         unsigned int i;
2850 
2851         /* This should always be true, but let's be sure. */
2852         info->sechdrs[0].sh_addr = 0;
2853 
2854         for (i = 1; i < info->hdr->e_shnum; i++) {
2855                 Elf_Shdr *shdr = &info->sechdrs[i];
2856                 if (shdr->sh_type != SHT_NOBITS
2857                     && info->len < shdr->sh_offset + shdr->sh_size) {
2858                         pr_err("Module len %lu truncated\n", info->len);
2859                         return -ENOEXEC;
2860                 }
2861 
2862                 /* Mark all sections sh_addr with their address in the
2863                    temporary image. */
2864                 shdr->sh_addr = (size_t)info->hdr + shdr->sh_offset;
2865 
2866 #ifndef CONFIG_MODULE_UNLOAD
2867                 /* Don't load .exit sections */
2868                 if (strstarts(info->secstrings+shdr->sh_name, ".exit"))
2869                         shdr->sh_flags &= ~(unsigned long)SHF_ALLOC;
2870 #endif
2871         }
2872 
2873         /* Track but don't keep modinfo and version sections. */
2874         if (flags & MODULE_INIT_IGNORE_MODVERSIONS)
2875                 info->index.vers = 0; /* Pretend no __versions section! */
2876         else
2877                 info->index.vers = find_sec(info, "__versions");
2878         info->index.info = find_sec(info, ".modinfo");
2879         info->sechdrs[info->index.info].sh_flags &= ~(unsigned long)SHF_ALLOC;
2880         info->sechdrs[info->index.vers].sh_flags &= ~(unsigned long)SHF_ALLOC;
2881         return 0;
2882 }
2883 
2884 /*
2885  * Set up our basic convenience variables (pointers to section headers,
2886  * search for module section index etc), and do some basic section
2887  * verification.
2888  *
2889  * Return the temporary module pointer (we'll replace it with the final
2890  * one when we move the module sections around).
2891  */
2892 static struct module *setup_load_info(struct load_info *info, int flags)
2893 {
2894         unsigned int i;
2895         int err;
2896         struct module *mod;
2897 
2898         /* Set up the convenience variables */
2899         info->sechdrs = (void *)info->hdr + info->hdr->e_shoff;
2900         info->secstrings = (void *)info->hdr
2901                 + info->sechdrs[info->hdr->e_shstrndx].sh_offset;
2902 
2903         err = rewrite_section_headers(info, flags);
2904         if (err)
2905                 return ERR_PTR(err);
2906 
2907         /* Find internal symbols and strings. */
2908         for (i = 1; i < info->hdr->e_shnum; i++) {
2909                 if (info->sechdrs[i].sh_type == SHT_SYMTAB) {
2910                         info->index.sym = i;
2911                         info->index.str = info->sechdrs[i].sh_link;
2912                         info->strtab = (char *)info->hdr
2913                                 + info->sechdrs[info->index.str].sh_offset;
2914                         break;
2915                 }
2916         }
2917 
2918         info->index.mod = find_sec(info, ".gnu.linkonce.this_module");
2919         if (!info->index.mod) {
2920                 pr_warn("No module found in object\n");
2921                 return ERR_PTR(-ENOEXEC);
2922         }
2923         /* This is temporary: point mod into copy of data. */
2924         mod = (void *)info->sechdrs[info->index.mod].sh_addr;
2925 
2926         if (info->index.sym == 0) {
2927                 pr_warn("%s: module has no symbols (stripped?)\n", mod->name);
2928                 return ERR_PTR(-ENOEXEC);
2929         }
2930 
2931         info->index.pcpu = find_pcpusec(info);
2932 
2933         /* Check module struct version now, before we try to use module. */
2934         if (!check_modstruct_version(info->sechdrs, info->index.vers, mod))
2935                 return ERR_PTR(-ENOEXEC);
2936 
2937         return mod;
2938 }
2939 
2940 static int check_modinfo(struct module *mod, struct load_info *info, int flags)
2941 {
2942         const char *modmagic = get_modinfo(info, "vermagic");
2943         int err;
2944 
2945         if (flags & MODULE_INIT_IGNORE_VERMAGIC)
2946                 modmagic = NULL;
2947 
2948         /* This is allowed: modprobe --force will invalidate it. */
2949         if (!modmagic) {
2950                 err = try_to_force_load(mod, "bad vermagic");
2951                 if (err)
2952                         return err;
2953         } else if (!same_magic(modmagic, vermagic, info->index.vers)) {
2954                 pr_err("%s: version magic '%s' should be '%s'\n",
2955                        mod->name, modmagic, vermagic);
2956                 return -ENOEXEC;
2957         }
2958 
2959         if (!get_modinfo(info, "intree")) {
2960                 if (!test_taint(TAINT_OOT_MODULE))
2961                         pr_warn("%s: loading out-of-tree module taints kernel.\n",
2962                                 mod->name);
2963                 add_taint_module(mod, TAINT_OOT_MODULE, LOCKDEP_STILL_OK);
2964         }
2965 
2966         if (get_modinfo(info, "staging")) {
2967                 add_taint_module(mod, TAINT_CRAP, LOCKDEP_STILL_OK);
2968                 pr_warn("%s: module is from the staging directory, the quality "
2969                         "is unknown, you have been warned.\n", mod->name);
2970         }
2971 
2972         err = find_livepatch_modinfo(mod, info);
2973         if (err)
2974                 return err;
2975 
2976         /* Set up license info based on the info section */
2977         set_license(mod, get_modinfo(info, "license"));
2978 
2979         return 0;
2980 }
2981 
2982 static int find_module_sections(struct module *mod, struct load_info *info)
2983 {
2984         mod->kp = section_objs(info, "__param",
2985                                sizeof(*mod->kp), &mod->num_kp);
2986         mod->syms = section_objs(info, "__ksymtab",
2987                                  sizeof(*mod->syms), &mod->num_syms);
2988         mod->crcs = section_addr(info, "__kcrctab");
2989         mod->gpl_syms = section_objs(info, "__ksymtab_gpl",
2990                                      sizeof(*mod->gpl_syms),
2991                                      &mod->num_gpl_syms);
2992         mod->gpl_crcs = section_addr(info, "__kcrctab_gpl");
2993         mod->gpl_future_syms = section_objs(info,
2994                                             "__ksymtab_gpl_future",
2995                                             sizeof(*mod->gpl_future_syms),
2996                                             &mod->num_gpl_future_syms);
2997         mod->gpl_future_crcs = section_addr(info, "__kcrctab_gpl_future");
2998 
2999 #ifdef CONFIG_UNUSED_SYMBOLS
3000         mod->unused_syms = section_objs(info, "__ksymtab_unused",
3001                                         sizeof(*mod->unused_syms),
3002                                         &mod->num_unused_syms);
3003         mod->unused_crcs = section_addr(info, "__kcrctab_unused");
3004         mod->unused_gpl_syms = section_objs(info, "__ksymtab_unused_gpl",
3005                                             sizeof(*mod->unused_gpl_syms),
3006                                             &mod->num_unused_gpl_syms);
3007         mod->unused_gpl_crcs = section_addr(info, "__kcrctab_unused_gpl");
3008 #endif
3009 #ifdef CONFIG_CONSTRUCTORS
3010         mod->ctors = section_objs(info, ".ctors",
3011                                   sizeof(*mod->ctors), &mod->num_ctors);
3012         if (!mod->ctors)
3013                 mod->ctors = section_objs(info, ".init_array",
3014                                 sizeof(*mod->ctors), &mod->num_ctors);
3015         else if (find_sec(info, ".init_array")) {
3016                 /*
3017                  * This shouldn't happen with same compiler and binutils
3018                  * building all parts of the module.
3019                  */
3020                 pr_warn("%s: has both .ctors and .init_array.\n",
3021                        mod->name);
3022                 return -EINVAL;
3023         }
3024 #endif
3025 
3026 #ifdef CONFIG_TRACEPOINTS
3027         mod->tracepoints_ptrs = section_objs(info, "__tracepoints_ptrs",
3028                                              sizeof(*mod->tracepoints_ptrs),
3029                                              &mod->num_tracepoints);
3030 #endif
3031 #ifdef HAVE_JUMP_LABEL
3032         mod->jump_entries = section_objs(info, "__jump_table",
3033                                         sizeof(*mod->jump_entries),
3034                                         &mod->num_jump_entries);
3035 #endif
3036 #ifdef CONFIG_EVENT_TRACING
3037         mod->trace_events = section_objs(info, "_ftrace_events",
3038                                          sizeof(*mod->trace_events),
3039                                          &mod->num_trace_events);
3040         mod->trace_enums = section_objs(info, "_ftrace_enum_map",
3041                                         sizeof(*mod->trace_enums),
3042                                         &mod->num_trace_enums);
3043 #endif
3044 #ifdef CONFIG_TRACING
3045         mod->trace_bprintk_fmt_start = section_objs(info, "__trace_printk_fmt",
3046                                          sizeof(*mod->trace_bprintk_fmt_start),
3047                                          &mod->num_trace_bprintk_fmt);
3048 #endif
3049 #ifdef CONFIG_FTRACE_MCOUNT_RECORD
3050         /* sechdrs[0].sh_size is always zero */
3051         mod->ftrace_callsites = section_objs(info, "__mcount_loc",
3052                                              sizeof(*mod->ftrace_callsites),
3053                                              &mod->num_ftrace_callsites);
3054 #endif
3055 
3056         mod->extable = section_objs(info, "__ex_table",
3057                                     sizeof(*mod->extable), &mod->num_exentries);
3058 
3059         if (section_addr(info, "__obsparm"))
3060                 pr_warn("%s: Ignoring obsolete parameters\n", mod->name);
3061 
3062         info->debug = section_objs(info, "__verbose",
3063                                    sizeof(*info->debug), &info->num_debug);
3064 
3065         return 0;
3066 }
3067 
3068 static int move_module(struct module *mod, struct load_info *info)
3069 {
3070         int i;
3071         void *ptr;
3072 
3073         /* Do the allocs. */
3074         ptr = module_alloc(mod->core_layout.size);
3075         /*
3076          * The pointer to this block is stored in the module structure
3077          * which is inside the block. Just mark it as not being a
3078          * leak.
3079          */
3080         kmemleak_not_leak(ptr);
3081         if (!ptr)
3082                 return -ENOMEM;
3083 
3084         memset(ptr, 0, mod->core_layout.size);
3085         mod->core_layout.base = ptr;
3086 
3087         if (mod->init_layout.size) {
3088                 ptr = module_alloc(mod->init_layout.size);
3089                 /*
3090                  * The pointer to this block is stored in the module structure
3091                  * which is inside the block. This block doesn't need to be
3092                  * scanned as it contains data and code that will be freed
3093                  * after the module is initialized.
3094                  */
3095                 kmemleak_ignore(ptr);
3096                 if (!ptr) {
3097                         module_memfree(mod->core_layout.base);
3098                         return -ENOMEM;
3099                 }
3100                 memset(ptr, 0, mod->init_layout.size);
3101                 mod->init_layout.base = ptr;
3102         } else
3103                 mod->init_layout.base = NULL;
3104 
3105         /* Transfer each section which specifies SHF_ALLOC */
3106         pr_debug("final section addresses:\n");
3107         for (i = 0; i < info->hdr->e_shnum; i++) {
3108                 void *dest;
3109                 Elf_Shdr *shdr = &info->sechdrs[i];
3110 
3111                 if (!(shdr->sh_flags & SHF_ALLOC))
3112                         continue;
3113 
3114                 if (shdr->sh_entsize & INIT_OFFSET_MASK)
3115                         dest = mod->init_layout.base
3116                                 + (shdr->sh_entsize & ~INIT_OFFSET_MASK);
3117                 else
3118                         dest = mod->core_layout.base + shdr->sh_entsize;
3119 
3120                 if (shdr->sh_type != SHT_NOBITS)
3121                         memcpy(dest, (void *)shdr->sh_addr, shdr->sh_size);
3122                 /* Update sh_addr to point to copy in image. */
3123                 shdr->sh_addr = (unsigned long)dest;
3124                 pr_debug("\t0x%lx %s\n",
3125                          (long)shdr->sh_addr, info->secstrings + shdr->sh_name);
3126         }
3127 
3128         return 0;
3129 }
3130 
3131 static int check_module_license_and_versions(struct module *mod)
3132 {
3133         int prev_taint = test_taint(TAINT_PROPRIETARY_MODULE);
3134 
3135         /*
3136          * ndiswrapper is under GPL by itself, but loads proprietary modules.
3137          * Don't use add_taint_module(), as it would prevent ndiswrapper from
3138          * using GPL-only symbols it needs.
3139          */
3140         if (strcmp(mod->name, "ndiswrapper") == 0)
3141                 add_taint(TAINT_PROPRIETARY_MODULE, LOCKDEP_NOW_UNRELIABLE);
3142 
3143         /* driverloader was caught wrongly pretending to be under GPL */
3144         if (strcmp(mod->name, "driverloader") == 0)
3145                 add_taint_module(mod, TAINT_PROPRIETARY_MODULE,
3146                                  LOCKDEP_NOW_UNRELIABLE);
3147 
3148         /* lve claims to be GPL but upstream won't provide source */
3149         if (strcmp(mod->name, "lve") == 0)
3150                 add_taint_module(mod, TAINT_PROPRIETARY_MODULE,
3151                                  LOCKDEP_NOW_UNRELIABLE);
3152 
3153         if (!prev_taint && test_taint(TAINT_PROPRIETARY_MODULE))
3154                 pr_warn("%s: module license taints kernel.\n", mod->name);
3155 
3156 #ifdef CONFIG_MODVERSIONS
3157         if ((mod->num_syms && !mod->crcs)
3158             || (mod->num_gpl_syms && !mod->gpl_crcs)
3159             || (mod->num_gpl_future_syms && !mod->gpl_future_crcs)
3160 #ifdef CONFIG_UNUSED_SYMBOLS
3161             || (mod->num_unused_syms && !mod->unused_crcs)
3162             || (mod->num_unused_gpl_syms && !mod->unused_gpl_crcs)
3163 #endif
3164                 ) {
3165                 return try_to_force_load(mod,
3166                                          "no versions for exported symbols");
3167         }
3168 #endif
3169         return 0;
3170 }
3171 
3172 static void flush_module_icache(const struct module *mod)
3173 {
3174         mm_segment_t old_fs;
3175 
3176         /* flush the icache in correct context */
3177         old_fs = get_fs();
3178         set_fs(KERNEL_DS);
3179 
3180         /*
3181          * Flush the instruction cache, since we've played with text.
3182          * Do it before processing of module parameters, so the module
3183          * can provide parameter accessor functions of its own.
3184          */
3185         if (mod->init_layout.base)
3186                 flush_icache_range((unsigned long)mod->init_layout.base,
3187                                    (unsigned long)mod->init_layout.base
3188                                    + mod->init_layout.size);
3189         flush_icache_range((unsigned long)mod->core_layout.base,
3190                            (unsigned long)mod->core_layout.base + mod->core_layout.size);
3191 
3192         set_fs(old_fs);
3193 }
3194 
3195 int __weak module_frob_arch_sections(Elf_Ehdr *hdr,
3196                                      Elf_Shdr *sechdrs,
3197                                      char *secstrings,
3198                                      struct module *mod)
3199 {
3200         return 0;
3201 }
3202 
3203 /* module_blacklist is a comma-separated list of module names */
3204 static char *module_blacklist;
3205 static bool blacklisted(char *module_name)
3206 {
3207         const char *p;
3208         size_t len;
3209 
3210         if (!module_blacklist)
3211                 return false;
3212 
3213         for (p = module_blacklist; *p; p += len) {
3214                 len = strcspn(p, ",");
3215                 if (strlen(module_name) == len && !memcmp(module_name, p, len))
3216                         return true;
3217                 if (p[len] == ',')
3218                         len++;
3219         }
3220         return false;
3221 }
3222 core_param(module_blacklist, module_blacklist, charp, 0400);
3223 
3224 static struct module *layout_and_allocate(struct load_info *info, int flags)
3225 {
3226         /* Module within temporary copy. */
3227         struct module *mod;
3228         unsigned int ndx;
3229         int err;
3230 
3231         mod = setup_load_info(info, flags);
3232         if (IS_ERR(mod))
3233                 return mod;
3234 
3235         if (blacklisted(mod->name))
3236                 return ERR_PTR(-EPERM);
3237 
3238         err = check_modinfo(mod, info, flags);
3239         if (err)
3240                 return ERR_PTR(err);
3241 
3242         /* Allow arches to frob section contents and sizes.  */
3243         err = module_frob_arch_sections(info->hdr, info->sechdrs,
3244                                         info->secstrings, mod);
3245         if (err < 0)
3246                 return ERR_PTR(err);
3247 
3248         /* We will do a special allocation for per-cpu sections later. */
3249         info->sechdrs[info->index.pcpu].sh_flags &= ~(unsigned long)SHF_ALLOC;
3250 
3251         /*
3252          * Mark ro_after_init section with SHF_RO_AFTER_INIT so that
3253          * layout_sections() can put it in the right place.
3254          * Note: ro_after_init sections also have SHF_{WRITE,ALLOC} set.
3255          */
3256         ndx = find_sec(info, ".data..ro_after_init");
3257         if (ndx)
3258                 info->sechdrs[ndx].sh_flags |= SHF_RO_AFTER_INIT;
3259 
3260         /* Determine total sizes, and put offsets in sh_entsize.  For now
3261            this is done generically; there doesn't appear to be any
3262            special cases for the architectures. */
3263         layout_sections(mod, info);
3264         layout_symtab(mod, info);
3265 
3266         /* Allocate and move to the final place */
3267         err = move_module(mod, info);
3268         if (err)
3269                 return ERR_PTR(err);
3270 
3271         /* Module has been copied to its final place now: return it. */
3272         mod = (void *)info->sechdrs[info->index.mod].sh_addr;
3273         kmemleak_load_module(mod, info);
3274         return mod;
3275 }
3276 
3277 /* mod is no longer valid after this! */
3278 static void module_deallocate(struct module *mod, struct load_info *info)
3279 {
3280         percpu_modfree(mod);
3281         module_arch_freeing_init(mod);
3282         module_memfree(mod->init_layout.base);
3283         module_memfree(mod->core_layout.base);
3284 }
3285 
3286 int __weak module_finalize(const Elf_Ehdr *hdr,
3287                            const Elf_Shdr *sechdrs,
3288                            struct module *me)
3289 {
3290         return 0;
3291 }
3292 
3293 static int post_relocation(struct module *mod, const struct load_info *info)
3294 {
3295         /* Sort exception table now relocations are done. */
3296         sort_extable(mod->extable, mod->extable + mod->num_exentries);
3297 
3298         /* Copy relocated percpu area over. */
3299         percpu_modcopy(mod, (void *)info->sechdrs[info->index.pcpu].sh_addr,
3300                        info->sechdrs[info->index.pcpu].sh_size);
3301 
3302         /* Setup kallsyms-specific fields. */
3303         add_kallsyms(mod, info);
3304 
3305         /* Arch-specific module finalizing. */
3306         return module_finalize(info->hdr, info->sechdrs, mod);
3307 }
3308 
3309 /* Is this module of this name done loading?  No locks held. */
3310 static bool finished_loading(const char *name)
3311 {
3312         struct module *mod;
3313         bool ret;
3314 
3315         /*
3316          * The module_mutex should not be a heavily contended lock;
3317          * if we get the occasional sleep here, we'll go an extra iteration
3318          * in the wait_event_interruptible(), which is harmless.
3319          */
3320         sched_annotate_sleep();
3321         mutex_lock(&module_mutex);
3322         mod = find_module_all(name, strlen(name), true);
3323         ret = !mod || mod->state == MODULE_STATE_LIVE
3324                 || mod->state == MODULE_STATE_GOING;
3325         mutex_unlock(&module_mutex);
3326 
3327         return ret;
3328 }
3329 
3330 /* Call module constructors. */
3331 static void do_mod_ctors(struct module *mod)
3332 {
3333 #ifdef CONFIG_CONSTRUCTORS
3334         unsigned long i;
3335 
3336         for (i = 0; i < mod->num_ctors; i++)
3337                 mod->ctors[i]();
3338 #endif
3339 }
3340 
3341 /* For freeing module_init on success, in case kallsyms traversing */
3342 struct mod_initfree {
3343         struct rcu_head rcu;
3344         void *module_init;
3345 };
3346 
3347 static void do_free_init(struct rcu_head *head)
3348 {
3349         struct mod_initfree *m = container_of(head, struct mod_initfree, rcu);
3350         module_memfree(m->module_init);
3351         kfree(m);
3352 }
3353 
3354 /*
3355  * This is where the real work happens.
3356  *
3357  * Keep it uninlined to provide a reliable breakpoint target, e.g. for the gdb
3358  * helper command 'lx-symbols'.
3359  */
3360 static noinline int do_init_module(struct module *mod)
3361 {
3362         int ret = 0;
3363         struct mod_initfree *freeinit;
3364 
3365         freeinit = kmalloc(sizeof(*freeinit), GFP_KERNEL);
3366         if (!freeinit) {
3367                 ret = -ENOMEM;
3368                 goto fail;
3369         }
3370         freeinit->module_init = mod->init_layout.base;
3371 
3372         /*
3373          * We want to find out whether @mod uses async during init.  Clear
3374          * PF_USED_ASYNC.  async_schedule*() will set it.
3375          */
3376         current->flags &= ~PF_USED_ASYNC;
3377 
3378         do_mod_ctors(mod);
3379         /* Start the module */
3380         if (mod->init != NULL)
3381                 ret = do_one_initcall(mod->init);
3382         if (ret < 0) {
3383                 goto fail_free_freeinit;
3384         }
3385         if (ret > 0) {
3386                 pr_warn("%s: '%s'->init suspiciously returned %d, it should "
3387                         "follow 0/-E convention\n"
3388                         "%s: loading module anyway...\n",
3389                         __func__, mod->name, ret, __func__);
3390                 dump_stack();
3391         }
3392 
3393         /* Now it's a first class citizen! */
3394         mod->state = MODULE_STATE_LIVE;
3395         blocking_notifier_call_chain(&module_notify_list,
3396                                      MODULE_STATE_LIVE, mod);
3397 
3398         /*
3399          * We need to finish all async code before the module init sequence
3400          * is done.  This has potential to deadlock.  For example, a newly
3401          * detected block device can trigger request_module() of the
3402          * default iosched from async probing task.  Once userland helper
3403          * reaches here, async_synchronize_full() will wait on the async
3404          * task waiting on request_module() and deadlock.
3405          *
3406          * This deadlock is avoided by perfomring async_synchronize_full()
3407          * iff module init queued any async jobs.  This isn't a full
3408          * solution as it will deadlock the same if module loading from
3409          * async jobs nests more than once; however, due to the various
3410          * constraints, this hack seems to be the best option for now.
3411          * Please refer to the following thread for details.
3412          *
3413          * http://thread.gmane.org/gmane.linux.kernel/1420814
3414          */
3415         if (!mod->async_probe_requested && (current->flags & PF_USED_ASYNC))
3416                 async_synchronize_full();
3417 
3418         mutex_lock(&module_mutex);
3419         /* Drop initial reference. */
3420         module_put(mod);
3421         trim_init_extable(mod);
3422 #ifdef CONFIG_KALLSYMS
3423         /* Switch to core kallsyms now init is done: kallsyms may be walking! */
3424         rcu_assign_pointer(mod->kallsyms, &mod->core_kallsyms);
3425 #endif
3426         module_enable_ro(mod, true);
3427         mod_tree_remove_init(mod);
3428         disable_ro_nx(&mod->init_layout);
3429         module_arch_freeing_init(mod);
3430         mod->init_layout.base = NULL;
3431         mod->init_layout.size = 0;
3432         mod->init_layout.ro_size = 0;
3433         mod->init_layout.ro_after_init_size = 0;
3434         mod->init_layout.text_size = 0;
3435         /*
3436          * We want to free module_init, but be aware that kallsyms may be
3437          * walking this with preempt disabled.  In all the failure paths, we
3438          * call synchronize_sched(), but we don't want to slow down the success
3439          * path, so use actual RCU here.
3440          */
3441         call_rcu_sched(&freeinit->rcu, do_free_init);
3442         mutex_unlock(&module_mutex);
3443         wake_up_all(&module_wq);
3444 
3445         return 0;
3446 
3447 fail_free_freeinit:
3448         kfree(freeinit);
3449 fail:
3450         /* Try to protect us from buggy refcounters. */
3451         mod->state = MODULE_STATE_GOING;
3452         synchronize_sched();
3453         module_put(mod);
3454         blocking_notifier_call_chain(&module_notify_list,
3455                                      MODULE_STATE_GOING, mod);
3456         klp_module_going(mod);
3457         ftrace_release_mod(mod);
3458         free_module(mod);
3459         wake_up_all(&module_wq);
3460         return ret;
3461 }
3462 
3463 static int may_init_module(void)
3464 {
3465         if (!capable(CAP_SYS_MODULE) || modules_disabled)
3466                 return -EPERM;
3467 
3468         return 0;
3469 }
3470 
3471 /*
3472  * We try to place it in the list now to make sure it's unique before
3473  * we dedicate too many resources.  In particular, temporary percpu
3474  * memory exhaustion.
3475  */
3476 static int add_unformed_module(struct module *mod)
3477 {
3478         int err;
3479         struct module *old;
3480 
3481         mod->state = MODULE_STATE_UNFORMED;
3482 
3483 again:
3484         mutex_lock(&module_mutex);
3485         old = find_module_all(mod->name, strlen(mod->name), true);
3486         if (old != NULL) {
3487                 if (old->state == MODULE_STATE_COMING
3488                     || old->state == MODULE_STATE_UNFORMED) {
3489                         /* Wait in case it fails to load. */
3490                         mutex_unlock(&module_mutex);
3491                         err = wait_event_interruptible(module_wq,
3492                                                finished_loading(mod->name));
3493                         if (err)
3494                                 goto out_unlocked;
3495                         goto again;
3496                 }
3497                 err = -EEXIST;
3498                 goto out;
3499         }
3500         mod_update_bounds(mod);
3501         list_add_rcu(&mod->list, &modules);
3502         mod_tree_insert(mod);
3503         err = 0;
3504 
3505 out:
3506         mutex_unlock(&module_mutex);
3507 out_unlocked:
3508         return err;
3509 }
3510 
3511 static int complete_formation(struct module *mod, struct load_info *info)
3512 {
3513         int err;
3514 
3515         mutex_lock(&module_mutex);
3516 
3517         /* Find duplicate symbols (must be called under lock). */
3518         err = verify_export_symbols(mod);
3519         if (err < 0)
3520                 goto out;
3521 
3522         /* This relies on module_mutex for list integrity. */
3523         module_bug_finalize(info->hdr, info->sechdrs, mod);
3524 
3525         module_enable_ro(mod, false);
3526         module_enable_nx(mod);
3527 
3528         /* Mark state as coming so strong_try_module_get() ignores us,
3529          * but kallsyms etc. can see us. */
3530         mod->state = MODULE_STATE_COMING;
3531         mutex_unlock(&module_mutex);
3532 
3533         return 0;
3534 
3535 out:
3536         mutex_unlock(&module_mutex);
3537         return err;
3538 }
3539 
3540 static int prepare_coming_module(struct module *mod)
3541 {
3542         int err;
3543 
3544         ftrace_module_enable(mod);
3545         err = klp_module_coming(mod);
3546         if (err)
3547                 return err;
3548 
3549         blocking_notifier_call_chain(&module_notify_list,
3550                                      MODULE_STATE_COMING, mod);
3551         return 0;
3552 }
3553 
3554 static int unknown_module_param_cb(char *param, char *val, const char *modname,
3555                                    void *arg)
3556 {
3557         struct module *mod = arg;
3558         int ret;
3559 
3560         if (strcmp(param, "async_probe") == 0) {
3561                 mod->async_probe_requested = true;
3562                 return 0;
3563         }
3564 
3565         /* Check for magic 'dyndbg' arg */
3566         ret = ddebug_dyndbg_module_param_cb(param, val, modname);
3567         if (ret != 0)
3568                 pr_warn("%s: unknown parameter '%s' ignored\n", modname, param);
3569         return 0;
3570 }
3571 
3572 /* Allocate and load the module: note that size of section 0 is always
3573    zero, and we rely on this for optional sections. */
3574 static int load_module(struct load_info *info, const char __user *uargs,
3575                        int flags)
3576 {
3577         struct module *mod;
3578         long err;
3579         char *after_dashes;
3580 
3581         err = module_sig_check(info, flags);
3582         if (err)
3583                 goto free_copy;
3584 
3585         err = elf_header_check(info);
3586         if (err)
3587                 goto free_copy;
3588 
3589         /* Figure out module layout, and allocate all the memory. */
3590         mod = layout_and_allocate(info, flags);
3591         if (IS_ERR(mod)) {
3592                 err = PTR_ERR(mod);
3593                 goto free_copy;
3594         }
3595 
3596         /* Reserve our place in the list. */
3597         err = add_unformed_module(mod);
3598         if (err)
3599                 goto free_module;
3600 
3601 #ifdef CONFIG_MODULE_SIG
3602         mod->sig_ok = info->sig_ok;
3603         if (!mod->sig_ok) {
3604                 pr_notice_once("%s: module verification failed: signature "
3605                                "and/or required key missing - tainting "
3606                                "kernel\n", mod->name);
3607                 add_taint_module(mod, TAINT_UNSIGNED_MODULE, LOCKDEP_STILL_OK);
3608         }
3609 #endif
3610 
3611         /* To avoid stressing percpu allocator, do this once we're unique. */
3612         err = percpu_modalloc(mod, info);
3613         if (err)
3614                 goto unlink_mod;
3615 
3616         /* Now module is in final location, initialize linked lists, etc. */
3617         err = module_unload_init(mod);
3618         if (err)
3619                 goto unlink_mod;
3620 
3621         init_param_lock(mod);
3622 
3623         /* Now we've got everything in the final locations, we can
3624          * find optional sections. */
3625         err = find_module_sections(mod, info);
3626         if (err)
3627                 goto free_unload;
3628 
3629         err = check_module_license_and_versions(mod);
3630         if (err)
3631                 goto free_unload;
3632 
3633         /* Set up MODINFO_ATTR fields */
3634         setup_modinfo(mod, info);
3635 
3636         /* Fix up syms, so that st_value is a pointer to location. */
3637         err = simplify_symbols(mod, info);
3638         if (err < 0)
3639                 goto free_modinfo;
3640 
3641         err = apply_relocations(mod, info);
3642         if (err < 0)
3643                 goto free_modinfo;
3644 
3645         err = post_relocation(mod, info);
3646         if (err < 0)
3647                 goto free_modinfo;
3648 
3649         flush_module_icache(mod);
3650 
3651         /* Now copy in args */
3652         mod->args = strndup_user(uargs, ~0UL >> 1);
3653         if (IS_ERR(mod->args)) {
3654                 err = PTR_ERR(mod->args);
3655                 goto free_arch_cleanup;
3656         }
3657 
3658         dynamic_debug_setup(info->debug, info->num_debug);
3659 
3660         /* Ftrace init must be called in the MODULE_STATE_UNFORMED state */
3661         ftrace_module_init(mod);
3662 
3663         /* Finally it's fully formed, ready to start executing. */
3664         err = complete_formation(mod, info);
3665         if (err)
3666                 goto ddebug_cleanup;
3667 
3668         err = prepare_coming_module(mod);
3669         if (err)
3670                 goto bug_cleanup;
3671 
3672         /* Module is ready to execute: parsing args may do that. */
3673         after_dashes = parse_args(mod->name, mod->args, mod->kp, mod->num_kp,
3674                                   -32768, 32767, mod,
3675                                   unknown_module_param_cb);
3676         if (IS_ERR(after_dashes)) {
3677                 err = PTR_ERR(after_dashes);
3678                 goto coming_cleanup;
3679         } else if (after_dashes) {
3680                 pr_warn("%s: parameters '%s' after `--' ignored\n",
3681                        mod->name, after_dashes);
3682         }
3683 
3684         /* Link in to syfs. */
3685         err = mod_sysfs_setup(mod, info, mod->kp, mod->num_kp);
3686         if (err < 0)
3687                 goto coming_cleanup;
3688 
3689         if (is_livepatch_module(mod)) {
3690                 err = copy_module_elf(mod, info);
3691                 if (err < 0)
3692                         goto sysfs_cleanup;
3693         }
3694 
3695         /* Get rid of temporary copy. */
3696         free_copy(info);
3697 
3698         /* Done! */
3699         trace_module_load(mod);
3700 
3701         return do_init_module(mod);
3702 
3703  sysfs_cleanup:
3704         mod_sysfs_teardown(mod);
3705  coming_cleanup:
3706         blocking_notifier_call_chain(&module_notify_list,
3707                                      MODULE_STATE_GOING, mod);
3708         klp_module_going(mod);
3709  bug_cleanup:
3710         /* module_bug_cleanup needs module_mutex protection */
3711         mutex_lock(&module_mutex);
3712         module_bug_cleanup(mod);
3713         mutex_unlock(&module_mutex);
3714 
3715         /* we can't deallocate the module until we clear memory protection */
3716         module_disable_ro(mod);
3717         module_disable_nx(mod);
3718 
3719  ddebug_cleanup:
3720         dynamic_debug_remove(info->debug);
3721         synchronize_sched();
3722         kfree(mod->args);
3723  free_arch_cleanup:
3724         module_arch_cleanup(mod);
3725  free_modinfo:
3726         free_modinfo(mod);
3727  free_unload:
3728         module_unload_free(mod);
3729  unlink_mod:
3730         mutex_lock(&module_mutex);
3731         /* Unlink carefully: kallsyms could be walking list. */
3732         list_del_rcu(&mod->list);
3733         mod_tree_remove(mod);
3734         wake_up_all(&module_wq);
3735         /* Wait for RCU-sched synchronizing before releasing mod->list. */
3736         synchronize_sched();
3737         mutex_unlock(&module_mutex);
3738  free_module:
3739         /*
3740          * Ftrace needs to clean up what it initialized.
3741          * This does nothing if ftrace_module_init() wasn't called,
3742          * but it must be called outside of module_mutex.
3743          */
3744         ftrace_release_mod(mod);
3745         /* Free lock-classes; relies on the preceding sync_rcu() */
3746         lockdep_free_key_range(mod->core_layout.base, mod->core_layout.size);
3747 
3748         module_deallocate(mod, info);
3749  free_copy:
3750         free_copy(info);
3751         return err;
3752 }
3753 
3754 SYSCALL_DEFINE3(init_module, void __user *, umod,
3755                 unsigned long, len, const char __user *, uargs)
3756 {
3757         int err;
3758         struct load_info info = { };
3759 
3760         err = may_init_module();
3761         if (err)
3762                 return err;
3763 
3764         pr_debug("init_module: umod=%p, len=%lu, uargs=%p\n",
3765                umod, len, uargs);
3766 
3767         err = copy_module_from_user(umod, len, &info);
3768         if (err)
3769                 return err;
3770 
3771         return load_module(&info, uargs, 0);
3772 }
3773 
3774 SYSCALL_DEFINE3(finit_module, int, fd, const char __user *, uargs, int, flags)
3775 {
3776         struct load_info info = { };
3777         loff_t size;
3778         void *hdr;
3779         int err;
3780 
3781         err = may_init_module();
3782         if (err)
3783                 return err;
3784 
3785         pr_debug("finit_module: fd=%d, uargs=%p, flags=%i\n", fd, uargs, flags);
3786 
3787         if (flags & ~(MODULE_INIT_IGNORE_MODVERSIONS
3788                       |MODULE_INIT_IGNORE_VERMAGIC))
3789                 return -EINVAL;
3790 
3791         err = kernel_read_file_from_fd(fd, &hdr, &size, INT_MAX,
3792                                        READING_MODULE);
3793         if (err)
3794                 return err;
3795         info.hdr = hdr;
3796         info.len = size;
3797 
3798         return load_module(&info, uargs, flags);
3799 }
3800 
3801 static inline int within(unsigned long addr, void *start, unsigned long size)
3802 {
3803         return ((void *)addr >= start && (void *)addr < start + size);
3804 }
3805 
3806 #ifdef CONFIG_KALLSYMS
3807 /*
3808  * This ignores the intensely annoying "mapping symbols" found
3809  * in ARM ELF files: $a, $t and $d.
3810  */
3811 static inline int is_arm_mapping_symbol(const char *str)
3812 {
3813         if (str[0] == '.' && str[1] == 'L')
3814                 return true;
3815         return str[0] == '$' && strchr("axtd", str[1])
3816                && (str[2] == '\0' || str[2] == '.');
3817 }
3818 
3819 static const char *symname(struct mod_kallsyms *kallsyms, unsigned int symnum)
3820 {
3821         return kallsyms->strtab + kallsyms->symtab[symnum].st_name;
3822 }
3823 
3824 static const char *get_ksymbol(struct module *mod,
3825                                unsigned long addr,
3826                                unsigned long *size,
3827                                unsigned long *offset)
3828 {
3829         unsigned int i, best = 0;
3830         unsigned long nextval;
3831         struct mod_kallsyms *kallsyms = rcu_dereference_sched(mod->kallsyms);
3832 
3833         /* At worse, next value is at end of module */
3834         if (within_module_init(addr, mod))
3835                 nextval = (unsigned long)mod->init_layout.base+mod->init_layout.text_size;
3836         else
3837                 nextval = (unsigned long)mod->core_layout.base+mod->core_layout.text_size;
3838 
3839         /* Scan for closest preceding symbol, and next symbol. (ELF
3840            starts real symbols at 1). */
3841         for (i = 1; i < kallsyms->num_symtab; i++) {
3842                 if (kallsyms->symtab[i].st_shndx == SHN_UNDEF)
3843                         continue;
3844 
3845                 /* We ignore unnamed symbols: they're uninformative
3846                  * and inserted at a whim. */
3847                 if (*symname(kallsyms, i) == '\0'
3848                     || is_arm_mapping_symbol(symname(kallsyms, i)))
3849                         continue;
3850 
3851                 if (kallsyms->symtab[i].st_value <= addr
3852                     && kallsyms->symtab[i].st_value > kallsyms->symtab[best].st_value)
3853                         best = i;
3854                 if (kallsyms->symtab[i].st_value > addr
3855                     && kallsyms->symtab[i].st_value < nextval)
3856                         nextval = kallsyms->symtab[i].st_value;
3857         }
3858 
3859         if (!best)
3860                 return NULL;
3861 
3862         if (size)
3863                 *size = nextval - kallsyms->symtab[best].st_value;
3864         if (offset)
3865                 *offset = addr - kallsyms->symtab[best].st_value;
3866         return symname(kallsyms, best);
3867 }
3868 
3869 /* For kallsyms to ask for address resolution.  NULL means not found.  Careful
3870  * not to lock to avoid deadlock on oopses, simply disable preemption. */
3871 const char *module_address_lookup(unsigned long addr,
3872                             unsigned long *size,
3873                             unsigned long *offset,
3874                             char **modname,
3875                             char *namebuf)
3876 {
3877         const char *ret = NULL;
3878         struct module *mod;
3879 
3880         preempt_disable();
3881         mod = __module_address(addr);
3882         if (mod) {
3883                 if (modname)
3884                         *modname = mod->name;
3885                 ret = get_ksymbol(mod, addr, size, offset);
3886         }
3887         /* Make a copy in here where it's safe */
3888         if (ret) {
3889                 strncpy(namebuf, ret, KSYM_NAME_LEN - 1);
3890                 ret = namebuf;
3891         }
3892         preempt_enable();
3893 
3894         return ret;
3895 }
3896 
3897 int lookup_module_symbol_name(unsigned long addr, char *symname)
3898 {
3899         struct module *mod;
3900 
3901         preempt_disable();
3902         list_for_each_entry_rcu(mod, &modules, list) {
3903                 if (mod->state == MODULE_STATE_UNFORMED)
3904                         continue;
3905                 if (within_module(addr, mod)) {
3906                         const char *sym;
3907 
3908                         sym = get_ksymbol(mod, addr, NULL, NULL);
3909                         if (!sym)
3910                                 goto out;
3911                         strlcpy(symname, sym, KSYM_NAME_LEN);
3912                         preempt_enable();
3913                         return 0;
3914                 }
3915         }
3916 out:
3917         preempt_enable();
3918         return -ERANGE;
3919 }
3920 
3921 int lookup_module_symbol_attrs(unsigned long addr, unsigned long *size,
3922                         unsigned long *offset, char *modname, char *name)
3923 {
3924         struct module *mod;
3925 
3926         preempt_disable();
3927         list_for_each_entry_rcu(mod, &modules, list) {
3928                 if (mod->state == MODULE_STATE_UNFORMED)
3929                         continue;
3930                 if (within_module(addr, mod)) {
3931                         const char *sym;
3932 
3933                         sym = get_ksymbol(mod, addr, size, offset);
3934                         if (!sym)
3935                                 goto out;
3936                         if (modname)
3937                                 strlcpy(modname, mod->name, MODULE_NAME_LEN);
3938                         if (name)
3939                                 strlcpy(name, sym, KSYM_NAME_LEN);
3940                         preempt_enable();
3941                         return 0;
3942                 }
3943         }
3944 out:
3945         preempt_enable();
3946         return -ERANGE;
3947 }
3948 
3949 int module_get_kallsym(unsigned int symnum, unsigned long *value, char *type,
3950                         char *name, char *module_name, int *exported)
3951 {
3952         struct module *mod;
3953 
3954         preempt_disable();
3955         list_for_each_entry_rcu(mod, &modules, list) {
3956                 struct mod_kallsyms *kallsyms;
3957 
3958                 if (mod->state == MODULE_STATE_UNFORMED)
3959                         continue;
3960                 kallsyms = rcu_dereference_sched(mod->kallsyms);
3961                 if (symnum < kallsyms->num_symtab) {
3962                         *value = kallsyms->symtab[symnum].st_value;
3963                         *type = kallsyms->symtab[symnum].st_info;
3964                         strlcpy(name, symname(kallsyms, symnum), KSYM_NAME_LEN);
3965                         strlcpy(module_name, mod->name, MODULE_NAME_LEN);
3966                         *exported = is_exported(name, *value, mod);
3967                         preempt_enable();
3968                         return 0;
3969                 }
3970                 symnum -= kallsyms->num_symtab;
3971         }
3972         preempt_enable();
3973         return -ERANGE;
3974 }
3975 
3976 static unsigned long mod_find_symname(struct module *mod, const char *name)
3977 {
3978         unsigned int i;
3979         struct mod_kallsyms *kallsyms = rcu_dereference_sched(mod->kallsyms);
3980 
3981         for (i = 0; i < kallsyms->num_symtab; i++)
3982                 if (strcmp(name, symname(kallsyms, i)) == 0 &&
3983                     kallsyms->symtab[i].st_info != 'U')
3984                         return kallsyms->symtab[i].st_value;
3985         return 0;
3986 }
3987 
3988 /* Look for this name: can be of form module:name. */
3989 unsigned long module_kallsyms_lookup_name(const char *name)
3990 {
3991         struct module *mod;
3992         char *colon;
3993         unsigned long ret = 0;
3994 
3995         /* Don't lock: we're in enough trouble already. */
3996         preempt_disable();
3997         if ((colon = strchr(name, ':')) != NULL) {
3998                 if ((mod = find_module_all(name, colon - name, false)) != NULL)
3999                         ret = mod_find_symname(mod, colon+1);
4000         } else {
4001                 list_for_each_entry_rcu(mod, &modules, list) {
4002                         if (mod->state == MODULE_STATE_UNFORMED)
4003                                 continue;
4004                         if ((ret = mod_find_symname(mod, name)) != 0)
4005                                 break;
4006                 }
4007         }
4008         preempt_enable();
4009         return ret;
4010 }
4011 
4012 int module_kallsyms_on_each_symbol(int (*fn)(void *, const char *,
4013                                              struct module *, unsigned long),
4014                                    void *data)
4015 {
4016         struct module *mod;
4017         unsigned int i;
4018         int ret;
4019 
4020         module_assert_mutex();
4021 
4022         list_for_each_entry(mod, &modules, list) {
4023                 /* We hold module_mutex: no need for rcu_dereference_sched */
4024                 struct mod_kallsyms *kallsyms = mod->kallsyms;
4025 
4026                 if (mod->state == MODULE_STATE_UNFORMED)
4027                         continue;
4028                 for (i = 0; i < kallsyms->num_symtab; i++) {
4029                         ret = fn(data, symname(kallsyms, i),
4030                                  mod, kallsyms->symtab[i].st_value);
4031                         if (ret != 0)
4032                                 return ret;
4033                 }
4034         }
4035         return 0;
4036 }
4037 #endif /* CONFIG_KALLSYMS */
4038 
4039 static char *module_flags(struct module *mod, char *buf)
4040 {
4041         int bx = 0;
4042 
4043         BUG_ON(mod->state == MODULE_STATE_UNFORMED);
4044         if (mod->taints ||
4045             mod->state == MODULE_STATE_GOING ||
4046             mod->state == MODULE_STATE_COMING) {
4047                 buf[bx++] = '(';
4048                 bx += module_flags_taint(mod, buf + bx);
4049                 /* Show a - for module-is-being-unloaded */
4050                 if (mod->state == MODULE_STATE_GOING)
4051                         buf[bx++] = '-';
4052                 /* Show a + for module-is-being-loaded */
4053                 if (mod->state == MODULE_STATE_COMING)
4054                         buf[bx++] = '+';
4055                 buf[bx++] = ')';
4056         }
4057         buf[bx] = '\0';
4058 
4059         return buf;
4060 }
4061 
4062 #ifdef CONFIG_PROC_FS
4063 /* Called by the /proc file system to return a list of modules. */
4064 static void *m_start(struct seq_file *m, loff_t *pos)
4065 {
4066         mutex_lock(&module_mutex);
4067         return seq_list_start(&modules, *pos);
4068 }
4069 
4070 static void *m_next(struct seq_file *m, void *p, loff_t *pos)
4071 {
4072         return seq_list_next(p, &modules, pos);
4073 }
4074 
4075 static void m_stop(struct seq_file *m, void *p)
4076 {
4077         mutex_unlock(&module_mutex);
4078 }
4079 
4080 static int m_show(struct seq_file *m, void *p)
4081 {
4082         struct module *mod = list_entry(p, struct module, list);
4083         char buf[8];
4084 
4085         /* We always ignore unformed modules. */
4086         if (mod->state == MODULE_STATE_UNFORMED)
4087                 return 0;
4088 
4089         seq_printf(m, "%s %u",
4090                    mod->name, mod->init_layout.size + mod->core_layout.size);
4091         print_unload_info(m, mod);
4092 
4093         /* Informative for users. */
4094         seq_printf(m, " %s",
4095                    mod->state == MODULE_STATE_GOING ? "Unloading" :
4096                    mod->state == MODULE_STATE_COMING ? "Loading" :
4097                    "Live");
4098         /* Used by oprofile and other similar tools. */
4099         seq_printf(m, " 0x%pK", mod->core_layout.base);
4100 
4101         /* Taints info */
4102         if (mod->taints)
4103                 seq_printf(m, " %s", module_flags(mod, buf));
4104 
4105         seq_puts(m, "\n");
4106         return 0;
4107 }
4108 
4109 /* Format: modulename size refcount deps address
4110 
4111    Where refcount is a number or -, and deps is a comma-separated list
4112    of depends or -.
4113 */
4114 static const struct seq_operations modules_op = {
4115         .start  = m_start,
4116         .next   = m_next,
4117         .stop   = m_stop,
4118         .show   = m_show
4119 };
4120 
4121 static int modules_open(struct inode *inode, struct file *file)
4122 {
4123         return seq_open(file, &modules_op);
4124 }
4125 
4126 static const struct file_operations proc_modules_operations = {
4127         .open           = modules_open,
4128         .read           = seq_read,
4129         .llseek         = seq_lseek,
4130         .release        = seq_release,
4131 };
4132 
4133 static int __init proc_modules_init(void)
4134 {
4135         proc_create("modules", 0, NULL, &proc_modules_operations);
4136         return 0;
4137 }
4138 module_init(proc_modules_init);
4139 #endif
4140 
4141 /* Given an address, look for it in the module exception tables. */
4142 const struct exception_table_entry *search_module_extables(unsigned long addr)
4143 {
4144         const struct exception_table_entry *e = NULL;
4145         struct module *mod;
4146 
4147         preempt_disable();
4148         list_for_each_entry_rcu(mod, &modules, list) {
4149                 if (mod->state == MODULE_STATE_UNFORMED)
4150                         continue;
4151                 if (mod->num_exentries == 0)
4152                         continue;
4153 
4154                 e = search_extable(mod->extable,
4155                                    mod->extable + mod->num_exentries - 1,
4156                                    addr);
4157                 if (e)
4158                         break;
4159         }
4160         preempt_enable();
4161 
4162         /* Now, if we found one, we are running inside it now, hence
4163            we cannot unload the module, hence no refcnt needed. */
4164         return e;
4165 }
4166 
4167 /*
4168  * is_module_address - is this address inside a module?
4169  * @addr: the address to check.
4170  *
4171  * See is_module_text_address() if you simply want to see if the address
4172  * is code (not data).
4173  */
4174 bool is_module_address(unsigned long addr)
4175 {
4176         bool ret;
4177 
4178         preempt_disable();
4179         ret = __module_address(addr) != NULL;
4180         preempt_enable();
4181 
4182         return ret;
4183 }
4184 
4185 /*
4186  * __module_address - get the module which contains an address.
4187  * @addr: the address.
4188  *
4189  * Must be called with preempt disabled or module mutex held so that
4190  * module doesn't get freed during this.
4191  */
4192 struct module *__module_address(unsigned long addr)
4193 {
4194         struct module *mod;
4195 
4196         if (addr < module_addr_min || addr > module_addr_max)
4197                 return NULL;
4198 
4199         module_assert_mutex_or_preempt();
4200 
4201         mod = mod_find(addr);
4202         if (mod) {
4203                 BUG_ON(!within_module(addr, mod));
4204                 if (mod->state == MODULE_STATE_UNFORMED)
4205                         mod = NULL;
4206         }
4207         return mod;
4208 }
4209 EXPORT_SYMBOL_GPL(__module_address);
4210 
4211 /*
4212  * is_module_text_address - is this address inside module code?
4213  * @addr: the address to check.
4214  *
4215  * See is_module_address() if you simply want to see if the address is
4216  * anywhere in a module.  See kernel_text_address() for testing if an
4217  * address corresponds to kernel or module code.
4218  */
4219 bool is_module_text_address(unsigned long addr)
4220 {
4221         bool ret;
4222 
4223         preempt_disable();
4224         ret = __module_text_address(addr) != NULL;
4225         preempt_enable();
4226 
4227         return ret;
4228 }
4229 
4230 /*
4231  * __module_text_address - get the module whose code contains an address.
4232  * @addr: the address.
4233  *
4234  * Must be called with preempt disabled or module mutex held so that
4235  * module doesn't get freed during this.
4236  */
4237 struct module *__module_text_address(unsigned long addr)
4238 {
4239         struct module *mod = __module_address(addr);
4240         if (mod) {
4241                 /* Make sure it's within the text section. */
4242                 if (!within(addr, mod->init_layout.base, mod->init_layout.text_size)
4243                     && !within(addr, mod->core_layout.base, mod->core_layout.text_size))
4244                         mod = NULL;
4245         }
4246         return mod;
4247 }
4248 EXPORT_SYMBOL_GPL(__module_text_address);
4249 
4250 /* Don't grab lock, we're oopsing. */
4251 void print_modules(void)
4252 {
4253         struct module *mod;
4254         char buf[8];
4255 
4256         printk(KERN_DEFAULT "Modules linked in:");
4257         /* Most callers should already have preempt disabled, but make sure */
4258         preempt_disable();
4259         list_for_each_entry_rcu(mod, &modules, list) {
4260                 if (mod->state == MODULE_STATE_UNFORMED)
4261                         continue;
4262                 pr_cont(" %s%s", mod->name, module_flags(mod, buf));
4263         }
4264         preempt_enable();
4265         if (last_unloaded_module[0])
4266                 pr_cont(" [last unloaded: %s]", last_unloaded_module);
4267         pr_cont("\n");
4268 }
4269 
4270 #ifdef CONFIG_MODVERSIONS
4271 /* Generate the signature for all relevant module structures here.
4272  * If these change, we don't want to try to parse the module. */
4273 void module_layout(struct module *mod,
4274                    struct modversion_info *ver,
4275                    struct kernel_param *kp,
4276                    struct kernel_symbol *ks,
4277                    struct tracepoint * const *tp)
4278 {
4279 }
4280 EXPORT_SYMBOL(module_layout);
4281 #endif
4282 

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