Version:  2.6.34 2.6.35 2.6.36 2.6.37 2.6.38 2.6.39 3.0 3.1 3.2 3.3 3.4 3.5 3.6 3.7 3.8 3.9 3.10 3.11 3.12 3.13 3.14

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/ftrace_event.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/stop_machine.h>
 46 #include <linux/device.h>
 47 #include <linux/string.h>
 48 #include <linux/mutex.h>
 49 #include <linux/rculist.h>
 50 #include <asm/uaccess.h>
 51 #include <asm/cacheflush.h>
 52 #include <asm/mmu_context.h>
 53 #include <linux/license.h>
 54 #include <asm/sections.h>
 55 #include <linux/tracepoint.h>
 56 #include <linux/ftrace.h>
 57 #include <linux/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/fips.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 /*
 86  * Given BASE and SIZE this macro calculates the number of pages the
 87  * memory regions occupies
 88  */
 89 #define MOD_NUMBER_OF_PAGES(BASE, SIZE) (((SIZE) > 0) ?         \
 90                 (PFN_DOWN((unsigned long)(BASE) + (SIZE) - 1) - \
 91                          PFN_DOWN((unsigned long)BASE) + 1)     \
 92                 : (0UL))
 93 
 94 /* If this is set, the section belongs in the init part of the module */
 95 #define INIT_OFFSET_MASK (1UL << (BITS_PER_LONG-1))
 96 
 97 /*
 98  * Mutex protects:
 99  * 1) List of modules (also safely readable with preempt_disable),
100  * 2) module_use links,
101  * 3) module_addr_min/module_addr_max.
102  * (delete uses stop_machine/add uses RCU list operations). */
103 DEFINE_MUTEX(module_mutex);
104 EXPORT_SYMBOL_GPL(module_mutex);
105 static LIST_HEAD(modules);
106 #ifdef CONFIG_KGDB_KDB
107 struct list_head *kdb_modules = &modules; /* kdb needs the list of modules */
108 #endif /* CONFIG_KGDB_KDB */
109 
110 #ifdef CONFIG_MODULE_SIG
111 #ifdef CONFIG_MODULE_SIG_FORCE
112 static bool sig_enforce = true;
113 #else
114 static bool sig_enforce = false;
115 
116 static int param_set_bool_enable_only(const char *val,
117                                       const struct kernel_param *kp)
118 {
119         int err;
120         bool test;
121         struct kernel_param dummy_kp = *kp;
122 
123         dummy_kp.arg = &test;
124 
125         err = param_set_bool(val, &dummy_kp);
126         if (err)
127                 return err;
128 
129         /* Don't let them unset it once it's set! */
130         if (!test && sig_enforce)
131                 return -EROFS;
132 
133         if (test)
134                 sig_enforce = true;
135         return 0;
136 }
137 
138 static const struct kernel_param_ops param_ops_bool_enable_only = {
139         .flags = KERNEL_PARAM_FL_NOARG,
140         .set = param_set_bool_enable_only,
141         .get = param_get_bool,
142 };
143 #define param_check_bool_enable_only param_check_bool
144 
145 module_param(sig_enforce, bool_enable_only, 0644);
146 #endif /* !CONFIG_MODULE_SIG_FORCE */
147 #endif /* CONFIG_MODULE_SIG */
148 
149 /* Block module loading/unloading? */
150 int modules_disabled = 0;
151 core_param(nomodule, modules_disabled, bint, 0);
152 
153 /* Waiting for a module to finish initializing? */
154 static DECLARE_WAIT_QUEUE_HEAD(module_wq);
155 
156 static BLOCKING_NOTIFIER_HEAD(module_notify_list);
157 
158 /* Bounds of module allocation, for speeding __module_address.
159  * Protected by module_mutex. */
160 static unsigned long module_addr_min = -1UL, module_addr_max = 0;
161 
162 int register_module_notifier(struct notifier_block * nb)
163 {
164         return blocking_notifier_chain_register(&module_notify_list, nb);
165 }
166 EXPORT_SYMBOL(register_module_notifier);
167 
168 int unregister_module_notifier(struct notifier_block * nb)
169 {
170         return blocking_notifier_chain_unregister(&module_notify_list, nb);
171 }
172 EXPORT_SYMBOL(unregister_module_notifier);
173 
174 struct load_info {
175         Elf_Ehdr *hdr;
176         unsigned long len;
177         Elf_Shdr *sechdrs;
178         char *secstrings, *strtab;
179         unsigned long symoffs, stroffs;
180         struct _ddebug *debug;
181         unsigned int num_debug;
182         bool sig_ok;
183         struct {
184                 unsigned int sym, str, mod, vers, info, pcpu;
185         } index;
186 };
187 
188 /* We require a truly strong try_module_get(): 0 means failure due to
189    ongoing or failed initialization etc. */
190 static inline int strong_try_module_get(struct module *mod)
191 {
192         BUG_ON(mod && mod->state == MODULE_STATE_UNFORMED);
193         if (mod && mod->state == MODULE_STATE_COMING)
194                 return -EBUSY;
195         if (try_module_get(mod))
196                 return 0;
197         else
198                 return -ENOENT;
199 }
200 
201 static inline void add_taint_module(struct module *mod, unsigned flag,
202                                     enum lockdep_ok lockdep_ok)
203 {
204         add_taint(flag, lockdep_ok);
205         mod->taints |= (1U << flag);
206 }
207 
208 /*
209  * A thread that wants to hold a reference to a module only while it
210  * is running can call this to safely exit.  nfsd and lockd use this.
211  */
212 void __module_put_and_exit(struct module *mod, long code)
213 {
214         module_put(mod);
215         do_exit(code);
216 }
217 EXPORT_SYMBOL(__module_put_and_exit);
218 
219 /* Find a module section: 0 means not found. */
220 static unsigned int find_sec(const struct load_info *info, const char *name)
221 {
222         unsigned int i;
223 
224         for (i = 1; i < info->hdr->e_shnum; i++) {
225                 Elf_Shdr *shdr = &info->sechdrs[i];
226                 /* Alloc bit cleared means "ignore it." */
227                 if ((shdr->sh_flags & SHF_ALLOC)
228                     && strcmp(info->secstrings + shdr->sh_name, name) == 0)
229                         return i;
230         }
231         return 0;
232 }
233 
234 /* Find a module section, or NULL. */
235 static void *section_addr(const struct load_info *info, const char *name)
236 {
237         /* Section 0 has sh_addr 0. */
238         return (void *)info->sechdrs[find_sec(info, name)].sh_addr;
239 }
240 
241 /* Find a module section, or NULL.  Fill in number of "objects" in section. */
242 static void *section_objs(const struct load_info *info,
243                           const char *name,
244                           size_t object_size,
245                           unsigned int *num)
246 {
247         unsigned int sec = find_sec(info, name);
248 
249         /* Section 0 has sh_addr 0 and sh_size 0. */
250         *num = info->sechdrs[sec].sh_size / object_size;
251         return (void *)info->sechdrs[sec].sh_addr;
252 }
253 
254 /* Provided by the linker */
255 extern const struct kernel_symbol __start___ksymtab[];
256 extern const struct kernel_symbol __stop___ksymtab[];
257 extern const struct kernel_symbol __start___ksymtab_gpl[];
258 extern const struct kernel_symbol __stop___ksymtab_gpl[];
259 extern const struct kernel_symbol __start___ksymtab_gpl_future[];
260 extern const struct kernel_symbol __stop___ksymtab_gpl_future[];
261 extern const unsigned long __start___kcrctab[];
262 extern const unsigned long __start___kcrctab_gpl[];
263 extern const unsigned long __start___kcrctab_gpl_future[];
264 #ifdef CONFIG_UNUSED_SYMBOLS
265 extern const struct kernel_symbol __start___ksymtab_unused[];
266 extern const struct kernel_symbol __stop___ksymtab_unused[];
267 extern const struct kernel_symbol __start___ksymtab_unused_gpl[];
268 extern const struct kernel_symbol __stop___ksymtab_unused_gpl[];
269 extern const unsigned long __start___kcrctab_unused[];
270 extern const unsigned long __start___kcrctab_unused_gpl[];
271 #endif
272 
273 #ifndef CONFIG_MODVERSIONS
274 #define symversion(base, idx) NULL
275 #else
276 #define symversion(base, idx) ((base != NULL) ? ((base) + (idx)) : NULL)
277 #endif
278 
279 static bool each_symbol_in_section(const struct symsearch *arr,
280                                    unsigned int arrsize,
281                                    struct module *owner,
282                                    bool (*fn)(const struct symsearch *syms,
283                                               struct module *owner,
284                                               void *data),
285                                    void *data)
286 {
287         unsigned int j;
288 
289         for (j = 0; j < arrsize; j++) {
290                 if (fn(&arr[j], owner, data))
291                         return true;
292         }
293 
294         return false;
295 }
296 
297 /* Returns true as soon as fn returns true, otherwise false. */
298 bool each_symbol_section(bool (*fn)(const struct symsearch *arr,
299                                     struct module *owner,
300                                     void *data),
301                          void *data)
302 {
303         struct module *mod;
304         static const struct symsearch arr[] = {
305                 { __start___ksymtab, __stop___ksymtab, __start___kcrctab,
306                   NOT_GPL_ONLY, false },
307                 { __start___ksymtab_gpl, __stop___ksymtab_gpl,
308                   __start___kcrctab_gpl,
309                   GPL_ONLY, false },
310                 { __start___ksymtab_gpl_future, __stop___ksymtab_gpl_future,
311                   __start___kcrctab_gpl_future,
312                   WILL_BE_GPL_ONLY, false },
313 #ifdef CONFIG_UNUSED_SYMBOLS
314                 { __start___ksymtab_unused, __stop___ksymtab_unused,
315                   __start___kcrctab_unused,
316                   NOT_GPL_ONLY, true },
317                 { __start___ksymtab_unused_gpl, __stop___ksymtab_unused_gpl,
318                   __start___kcrctab_unused_gpl,
319                   GPL_ONLY, true },
320 #endif
321         };
322 
323         if (each_symbol_in_section(arr, ARRAY_SIZE(arr), NULL, fn, data))
324                 return true;
325 
326         list_for_each_entry_rcu(mod, &modules, list) {
327                 struct symsearch arr[] = {
328                         { mod->syms, mod->syms + mod->num_syms, mod->crcs,
329                           NOT_GPL_ONLY, false },
330                         { mod->gpl_syms, mod->gpl_syms + mod->num_gpl_syms,
331                           mod->gpl_crcs,
332                           GPL_ONLY, false },
333                         { mod->gpl_future_syms,
334                           mod->gpl_future_syms + mod->num_gpl_future_syms,
335                           mod->gpl_future_crcs,
336                           WILL_BE_GPL_ONLY, false },
337 #ifdef CONFIG_UNUSED_SYMBOLS
338                         { mod->unused_syms,
339                           mod->unused_syms + mod->num_unused_syms,
340                           mod->unused_crcs,
341                           NOT_GPL_ONLY, true },
342                         { mod->unused_gpl_syms,
343                           mod->unused_gpl_syms + mod->num_unused_gpl_syms,
344                           mod->unused_gpl_crcs,
345                           GPL_ONLY, true },
346 #endif
347                 };
348 
349                 if (mod->state == MODULE_STATE_UNFORMED)
350                         continue;
351 
352                 if (each_symbol_in_section(arr, ARRAY_SIZE(arr), mod, fn, data))
353                         return true;
354         }
355         return false;
356 }
357 EXPORT_SYMBOL_GPL(each_symbol_section);
358 
359 struct find_symbol_arg {
360         /* Input */
361         const char *name;
362         bool gplok;
363         bool warn;
364 
365         /* Output */
366         struct module *owner;
367         const unsigned long *crc;
368         const struct kernel_symbol *sym;
369 };
370 
371 static bool check_symbol(const struct symsearch *syms,
372                                  struct module *owner,
373                                  unsigned int symnum, void *data)
374 {
375         struct find_symbol_arg *fsa = data;
376 
377         if (!fsa->gplok) {
378                 if (syms->licence == GPL_ONLY)
379                         return false;
380                 if (syms->licence == WILL_BE_GPL_ONLY && fsa->warn) {
381                         pr_warn("Symbol %s is being used by a non-GPL module, "
382                                 "which will not be allowed in the future\n",
383                                 fsa->name);
384                 }
385         }
386 
387 #ifdef CONFIG_UNUSED_SYMBOLS
388         if (syms->unused && fsa->warn) {
389                 pr_warn("Symbol %s is marked as UNUSED, however this module is "
390                         "using it.\n", fsa->name);
391                 pr_warn("This symbol will go away in the future.\n");
392                 pr_warn("Please evalute if this is the right api to use and if "
393                         "it really is, submit a report the linux kernel "
394                         "mailinglist together with submitting your code for "
395                         "inclusion.\n");
396         }
397 #endif
398 
399         fsa->owner = owner;
400         fsa->crc = symversion(syms->crcs, symnum);
401         fsa->sym = &syms->start[symnum];
402         return true;
403 }
404 
405 static int cmp_name(const void *va, const void *vb)
406 {
407         const char *a;
408         const struct kernel_symbol *b;
409         a = va; b = vb;
410         return strcmp(a, b->name);
411 }
412 
413 static bool find_symbol_in_section(const struct symsearch *syms,
414                                    struct module *owner,
415                                    void *data)
416 {
417         struct find_symbol_arg *fsa = data;
418         struct kernel_symbol *sym;
419 
420         sym = bsearch(fsa->name, syms->start, syms->stop - syms->start,
421                         sizeof(struct kernel_symbol), cmp_name);
422 
423         if (sym != NULL && check_symbol(syms, owner, sym - syms->start, data))
424                 return true;
425 
426         return false;
427 }
428 
429 /* Find a symbol and return it, along with, (optional) crc and
430  * (optional) module which owns it.  Needs preempt disabled or module_mutex. */
431 const struct kernel_symbol *find_symbol(const char *name,
432                                         struct module **owner,
433                                         const unsigned long **crc,
434                                         bool gplok,
435                                         bool warn)
436 {
437         struct find_symbol_arg fsa;
438 
439         fsa.name = name;
440         fsa.gplok = gplok;
441         fsa.warn = warn;
442 
443         if (each_symbol_section(find_symbol_in_section, &fsa)) {
444                 if (owner)
445                         *owner = fsa.owner;
446                 if (crc)
447                         *crc = fsa.crc;
448                 return fsa.sym;
449         }
450 
451         pr_debug("Failed to find symbol %s\n", name);
452         return NULL;
453 }
454 EXPORT_SYMBOL_GPL(find_symbol);
455 
456 /* Search for module by name: must hold module_mutex. */
457 static struct module *find_module_all(const char *name, size_t len,
458                                       bool even_unformed)
459 {
460         struct module *mod;
461 
462         list_for_each_entry(mod, &modules, list) {
463                 if (!even_unformed && mod->state == MODULE_STATE_UNFORMED)
464                         continue;
465                 if (strlen(mod->name) == len && !memcmp(mod->name, name, len))
466                         return mod;
467         }
468         return NULL;
469 }
470 
471 struct module *find_module(const char *name)
472 {
473         return find_module_all(name, strlen(name), false);
474 }
475 EXPORT_SYMBOL_GPL(find_module);
476 
477 #ifdef CONFIG_SMP
478 
479 static inline void __percpu *mod_percpu(struct module *mod)
480 {
481         return mod->percpu;
482 }
483 
484 static int percpu_modalloc(struct module *mod, struct load_info *info)
485 {
486         Elf_Shdr *pcpusec = &info->sechdrs[info->index.pcpu];
487         unsigned long align = pcpusec->sh_addralign;
488 
489         if (!pcpusec->sh_size)
490                 return 0;
491 
492         if (align > PAGE_SIZE) {
493                 pr_warn("%s: per-cpu alignment %li > %li\n",
494                         mod->name, align, PAGE_SIZE);
495                 align = PAGE_SIZE;
496         }
497 
498         mod->percpu = __alloc_reserved_percpu(pcpusec->sh_size, align);
499         if (!mod->percpu) {
500                 pr_warn("%s: Could not allocate %lu bytes percpu data\n",
501                         mod->name, (unsigned long)pcpusec->sh_size);
502                 return -ENOMEM;
503         }
504         mod->percpu_size = pcpusec->sh_size;
505         return 0;
506 }
507 
508 static void percpu_modfree(struct module *mod)
509 {
510         free_percpu(mod->percpu);
511 }
512 
513 static unsigned int find_pcpusec(struct load_info *info)
514 {
515         return find_sec(info, ".data..percpu");
516 }
517 
518 static void percpu_modcopy(struct module *mod,
519                            const void *from, unsigned long size)
520 {
521         int cpu;
522 
523         for_each_possible_cpu(cpu)
524                 memcpy(per_cpu_ptr(mod->percpu, cpu), from, size);
525 }
526 
527 /**
528  * is_module_percpu_address - test whether address is from module static percpu
529  * @addr: address to test
530  *
531  * Test whether @addr belongs to module static percpu area.
532  *
533  * RETURNS:
534  * %true if @addr is from module static percpu area
535  */
536 bool is_module_percpu_address(unsigned long addr)
537 {
538         struct module *mod;
539         unsigned int cpu;
540 
541         preempt_disable();
542 
543         list_for_each_entry_rcu(mod, &modules, list) {
544                 if (mod->state == MODULE_STATE_UNFORMED)
545                         continue;
546                 if (!mod->percpu_size)
547                         continue;
548                 for_each_possible_cpu(cpu) {
549                         void *start = per_cpu_ptr(mod->percpu, cpu);
550 
551                         if ((void *)addr >= start &&
552                             (void *)addr < start + mod->percpu_size) {
553                                 preempt_enable();
554                                 return true;
555                         }
556                 }
557         }
558 
559         preempt_enable();
560         return false;
561 }
562 
563 #else /* ... !CONFIG_SMP */
564 
565 static inline void __percpu *mod_percpu(struct module *mod)
566 {
567         return NULL;
568 }
569 static int percpu_modalloc(struct module *mod, struct load_info *info)
570 {
571         /* UP modules shouldn't have this section: ENOMEM isn't quite right */
572         if (info->sechdrs[info->index.pcpu].sh_size != 0)
573                 return -ENOMEM;
574         return 0;
575 }
576 static inline void percpu_modfree(struct module *mod)
577 {
578 }
579 static unsigned int find_pcpusec(struct load_info *info)
580 {
581         return 0;
582 }
583 static inline void percpu_modcopy(struct module *mod,
584                                   const void *from, unsigned long size)
585 {
586         /* pcpusec should be 0, and size of that section should be 0. */
587         BUG_ON(size != 0);
588 }
589 bool is_module_percpu_address(unsigned long addr)
590 {
591         return false;
592 }
593 
594 #endif /* CONFIG_SMP */
595 
596 #define MODINFO_ATTR(field)     \
597 static void setup_modinfo_##field(struct module *mod, const char *s)  \
598 {                                                                     \
599         mod->field = kstrdup(s, GFP_KERNEL);                          \
600 }                                                                     \
601 static ssize_t show_modinfo_##field(struct module_attribute *mattr,   \
602                         struct module_kobject *mk, char *buffer)      \
603 {                                                                     \
604         return scnprintf(buffer, PAGE_SIZE, "%s\n", mk->mod->field);  \
605 }                                                                     \
606 static int modinfo_##field##_exists(struct module *mod)               \
607 {                                                                     \
608         return mod->field != NULL;                                    \
609 }                                                                     \
610 static void free_modinfo_##field(struct module *mod)                  \
611 {                                                                     \
612         kfree(mod->field);                                            \
613         mod->field = NULL;                                            \
614 }                                                                     \
615 static struct module_attribute modinfo_##field = {                    \
616         .attr = { .name = __stringify(field), .mode = 0444 },         \
617         .show = show_modinfo_##field,                                 \
618         .setup = setup_modinfo_##field,                               \
619         .test = modinfo_##field##_exists,                             \
620         .free = free_modinfo_##field,                                 \
621 };
622 
623 MODINFO_ATTR(version);
624 MODINFO_ATTR(srcversion);
625 
626 static char last_unloaded_module[MODULE_NAME_LEN+1];
627 
628 #ifdef CONFIG_MODULE_UNLOAD
629 
630 EXPORT_TRACEPOINT_SYMBOL(module_get);
631 
632 /* Init the unload section of the module. */
633 static int module_unload_init(struct module *mod)
634 {
635         mod->refptr = alloc_percpu(struct module_ref);
636         if (!mod->refptr)
637                 return -ENOMEM;
638 
639         INIT_LIST_HEAD(&mod->source_list);
640         INIT_LIST_HEAD(&mod->target_list);
641 
642         /* Hold reference count during initialization. */
643         __this_cpu_write(mod->refptr->incs, 1);
644 
645         return 0;
646 }
647 
648 /* Does a already use b? */
649 static int already_uses(struct module *a, struct module *b)
650 {
651         struct module_use *use;
652 
653         list_for_each_entry(use, &b->source_list, source_list) {
654                 if (use->source == a) {
655                         pr_debug("%s uses %s!\n", a->name, b->name);
656                         return 1;
657                 }
658         }
659         pr_debug("%s does not use %s!\n", a->name, b->name);
660         return 0;
661 }
662 
663 /*
664  * Module a uses b
665  *  - we add 'a' as a "source", 'b' as a "target" of module use
666  *  - the module_use is added to the list of 'b' sources (so
667  *    'b' can walk the list to see who sourced them), and of 'a'
668  *    targets (so 'a' can see what modules it targets).
669  */
670 static int add_module_usage(struct module *a, struct module *b)
671 {
672         struct module_use *use;
673 
674         pr_debug("Allocating new usage for %s.\n", a->name);
675         use = kmalloc(sizeof(*use), GFP_ATOMIC);
676         if (!use) {
677                 pr_warn("%s: out of memory loading\n", a->name);
678                 return -ENOMEM;
679         }
680 
681         use->source = a;
682         use->target = b;
683         list_add(&use->source_list, &b->source_list);
684         list_add(&use->target_list, &a->target_list);
685         return 0;
686 }
687 
688 /* Module a uses b: caller needs module_mutex() */
689 int ref_module(struct module *a, struct module *b)
690 {
691         int err;
692 
693         if (b == NULL || already_uses(a, b))
694                 return 0;
695 
696         /* If module isn't available, we fail. */
697         err = strong_try_module_get(b);
698         if (err)
699                 return err;
700 
701         err = add_module_usage(a, b);
702         if (err) {
703                 module_put(b);
704                 return err;
705         }
706         return 0;
707 }
708 EXPORT_SYMBOL_GPL(ref_module);
709 
710 /* Clear the unload stuff of the module. */
711 static void module_unload_free(struct module *mod)
712 {
713         struct module_use *use, *tmp;
714 
715         mutex_lock(&module_mutex);
716         list_for_each_entry_safe(use, tmp, &mod->target_list, target_list) {
717                 struct module *i = use->target;
718                 pr_debug("%s unusing %s\n", mod->name, i->name);
719                 module_put(i);
720                 list_del(&use->source_list);
721                 list_del(&use->target_list);
722                 kfree(use);
723         }
724         mutex_unlock(&module_mutex);
725 
726         free_percpu(mod->refptr);
727 }
728 
729 #ifdef CONFIG_MODULE_FORCE_UNLOAD
730 static inline int try_force_unload(unsigned int flags)
731 {
732         int ret = (flags & O_TRUNC);
733         if (ret)
734                 add_taint(TAINT_FORCED_RMMOD, LOCKDEP_NOW_UNRELIABLE);
735         return ret;
736 }
737 #else
738 static inline int try_force_unload(unsigned int flags)
739 {
740         return 0;
741 }
742 #endif /* CONFIG_MODULE_FORCE_UNLOAD */
743 
744 struct stopref
745 {
746         struct module *mod;
747         int flags;
748         int *forced;
749 };
750 
751 /* Whole machine is stopped with interrupts off when this runs. */
752 static int __try_stop_module(void *_sref)
753 {
754         struct stopref *sref = _sref;
755 
756         /* If it's not unused, quit unless we're forcing. */
757         if (module_refcount(sref->mod) != 0) {
758                 if (!(*sref->forced = try_force_unload(sref->flags)))
759                         return -EWOULDBLOCK;
760         }
761 
762         /* Mark it as dying. */
763         sref->mod->state = MODULE_STATE_GOING;
764         return 0;
765 }
766 
767 static int try_stop_module(struct module *mod, int flags, int *forced)
768 {
769         struct stopref sref = { mod, flags, forced };
770 
771         return stop_machine(__try_stop_module, &sref, NULL);
772 }
773 
774 unsigned long module_refcount(struct module *mod)
775 {
776         unsigned long incs = 0, decs = 0;
777         int cpu;
778 
779         for_each_possible_cpu(cpu)
780                 decs += per_cpu_ptr(mod->refptr, cpu)->decs;
781         /*
782          * ensure the incs are added up after the decs.
783          * module_put ensures incs are visible before decs with smp_wmb.
784          *
785          * This 2-count scheme avoids the situation where the refcount
786          * for CPU0 is read, then CPU0 increments the module refcount,
787          * then CPU1 drops that refcount, then the refcount for CPU1 is
788          * read. We would record a decrement but not its corresponding
789          * increment so we would see a low count (disaster).
790          *
791          * Rare situation? But module_refcount can be preempted, and we
792          * might be tallying up 4096+ CPUs. So it is not impossible.
793          */
794         smp_rmb();
795         for_each_possible_cpu(cpu)
796                 incs += per_cpu_ptr(mod->refptr, cpu)->incs;
797         return incs - decs;
798 }
799 EXPORT_SYMBOL(module_refcount);
800 
801 /* This exists whether we can unload or not */
802 static void free_module(struct module *mod);
803 
804 SYSCALL_DEFINE2(delete_module, const char __user *, name_user,
805                 unsigned int, flags)
806 {
807         struct module *mod;
808         char name[MODULE_NAME_LEN];
809         int ret, forced = 0;
810 
811         if (!capable(CAP_SYS_MODULE) || modules_disabled)
812                 return -EPERM;
813 
814         if (strncpy_from_user(name, name_user, MODULE_NAME_LEN-1) < 0)
815                 return -EFAULT;
816         name[MODULE_NAME_LEN-1] = '\0';
817 
818         if (!(flags & O_NONBLOCK))
819                 pr_warn("waiting module removal not supported: please upgrade\n");
820 
821         if (mutex_lock_interruptible(&module_mutex) != 0)
822                 return -EINTR;
823 
824         mod = find_module(name);
825         if (!mod) {
826                 ret = -ENOENT;
827                 goto out;
828         }
829 
830         if (!list_empty(&mod->source_list)) {
831                 /* Other modules depend on us: get rid of them first. */
832                 ret = -EWOULDBLOCK;
833                 goto out;
834         }
835 
836         /* Doing init or already dying? */
837         if (mod->state != MODULE_STATE_LIVE) {
838                 /* FIXME: if (force), slam module count damn the torpedoes */
839                 pr_debug("%s already dying\n", mod->name);
840                 ret = -EBUSY;
841                 goto out;
842         }
843 
844         /* If it has an init func, it must have an exit func to unload */
845         if (mod->init && !mod->exit) {
846                 forced = try_force_unload(flags);
847                 if (!forced) {
848                         /* This module can't be removed */
849                         ret = -EBUSY;
850                         goto out;
851                 }
852         }
853 
854         /* Stop the machine so refcounts can't move and disable module. */
855         ret = try_stop_module(mod, flags, &forced);
856         if (ret != 0)
857                 goto out;
858 
859         mutex_unlock(&module_mutex);
860         /* Final destruction now no one is using it. */
861         if (mod->exit != NULL)
862                 mod->exit();
863         blocking_notifier_call_chain(&module_notify_list,
864                                      MODULE_STATE_GOING, mod);
865         async_synchronize_full();
866 
867         /* Store the name of the last unloaded module for diagnostic purposes */
868         strlcpy(last_unloaded_module, mod->name, sizeof(last_unloaded_module));
869 
870         free_module(mod);
871         return 0;
872 out:
873         mutex_unlock(&module_mutex);
874         return ret;
875 }
876 
877 static inline void print_unload_info(struct seq_file *m, struct module *mod)
878 {
879         struct module_use *use;
880         int printed_something = 0;
881 
882         seq_printf(m, " %lu ", module_refcount(mod));
883 
884         /* Always include a trailing , so userspace can differentiate
885            between this and the old multi-field proc format. */
886         list_for_each_entry(use, &mod->source_list, source_list) {
887                 printed_something = 1;
888                 seq_printf(m, "%s,", use->source->name);
889         }
890 
891         if (mod->init != NULL && mod->exit == NULL) {
892                 printed_something = 1;
893                 seq_printf(m, "[permanent],");
894         }
895 
896         if (!printed_something)
897                 seq_printf(m, "-");
898 }
899 
900 void __symbol_put(const char *symbol)
901 {
902         struct module *owner;
903 
904         preempt_disable();
905         if (!find_symbol(symbol, &owner, NULL, true, false))
906                 BUG();
907         module_put(owner);
908         preempt_enable();
909 }
910 EXPORT_SYMBOL(__symbol_put);
911 
912 /* Note this assumes addr is a function, which it currently always is. */
913 void symbol_put_addr(void *addr)
914 {
915         struct module *modaddr;
916         unsigned long a = (unsigned long)dereference_function_descriptor(addr);
917 
918         if (core_kernel_text(a))
919                 return;
920 
921         /* module_text_address is safe here: we're supposed to have reference
922          * to module from symbol_get, so it can't go away. */
923         modaddr = __module_text_address(a);
924         BUG_ON(!modaddr);
925         module_put(modaddr);
926 }
927 EXPORT_SYMBOL_GPL(symbol_put_addr);
928 
929 static ssize_t show_refcnt(struct module_attribute *mattr,
930                            struct module_kobject *mk, char *buffer)
931 {
932         return sprintf(buffer, "%lu\n", module_refcount(mk->mod));
933 }
934 
935 static struct module_attribute modinfo_refcnt =
936         __ATTR(refcnt, 0444, show_refcnt, NULL);
937 
938 void __module_get(struct module *module)
939 {
940         if (module) {
941                 preempt_disable();
942                 __this_cpu_inc(module->refptr->incs);
943                 trace_module_get(module, _RET_IP_);
944                 preempt_enable();
945         }
946 }
947 EXPORT_SYMBOL(__module_get);
948 
949 bool try_module_get(struct module *module)
950 {
951         bool ret = true;
952 
953         if (module) {
954                 preempt_disable();
955 
956                 if (likely(module_is_live(module))) {
957                         __this_cpu_inc(module->refptr->incs);
958                         trace_module_get(module, _RET_IP_);
959                 } else
960                         ret = false;
961 
962                 preempt_enable();
963         }
964         return ret;
965 }
966 EXPORT_SYMBOL(try_module_get);
967 
968 void module_put(struct module *module)
969 {
970         if (module) {
971                 preempt_disable();
972                 smp_wmb(); /* see comment in module_refcount */
973                 __this_cpu_inc(module->refptr->decs);
974 
975                 trace_module_put(module, _RET_IP_);
976                 preempt_enable();
977         }
978 }
979 EXPORT_SYMBOL(module_put);
980 
981 #else /* !CONFIG_MODULE_UNLOAD */
982 static inline void print_unload_info(struct seq_file *m, struct module *mod)
983 {
984         /* We don't know the usage count, or what modules are using. */
985         seq_printf(m, " - -");
986 }
987 
988 static inline void module_unload_free(struct module *mod)
989 {
990 }
991 
992 int ref_module(struct module *a, struct module *b)
993 {
994         return strong_try_module_get(b);
995 }
996 EXPORT_SYMBOL_GPL(ref_module);
997 
998 static inline int module_unload_init(struct module *mod)
999 {
1000         return 0;
1001 }
1002 #endif /* CONFIG_MODULE_UNLOAD */
1003 
1004 static size_t module_flags_taint(struct module *mod, char *buf)
1005 {
1006         size_t l = 0;
1007 
1008         if (mod->taints & (1 << TAINT_PROPRIETARY_MODULE))
1009                 buf[l++] = 'P';
1010         if (mod->taints & (1 << TAINT_OOT_MODULE))
1011                 buf[l++] = 'O';
1012         if (mod->taints & (1 << TAINT_FORCED_MODULE))
1013                 buf[l++] = 'F';
1014         if (mod->taints & (1 << TAINT_CRAP))
1015                 buf[l++] = 'C';
1016         /*
1017          * TAINT_FORCED_RMMOD: could be added.
1018          * TAINT_UNSAFE_SMP, TAINT_MACHINE_CHECK, TAINT_BAD_PAGE don't
1019          * apply to modules.
1020          */
1021         return l;
1022 }
1023 
1024 static ssize_t show_initstate(struct module_attribute *mattr,
1025                               struct module_kobject *mk, char *buffer)
1026 {
1027         const char *state = "unknown";
1028 
1029         switch (mk->mod->state) {
1030         case MODULE_STATE_LIVE:
1031                 state = "live";
1032                 break;
1033         case MODULE_STATE_COMING:
1034                 state = "coming";
1035                 break;
1036         case MODULE_STATE_GOING:
1037                 state = "going";
1038                 break;
1039         default:
1040                 BUG();
1041         }
1042         return sprintf(buffer, "%s\n", state);
1043 }
1044 
1045 static struct module_attribute modinfo_initstate =
1046         __ATTR(initstate, 0444, show_initstate, NULL);
1047 
1048 static ssize_t store_uevent(struct module_attribute *mattr,
1049                             struct module_kobject *mk,
1050                             const char *buffer, size_t count)
1051 {
1052         enum kobject_action action;
1053 
1054         if (kobject_action_type(buffer, count, &action) == 0)
1055                 kobject_uevent(&mk->kobj, action);
1056         return count;
1057 }
1058 
1059 struct module_attribute module_uevent =
1060         __ATTR(uevent, 0200, NULL, store_uevent);
1061 
1062 static ssize_t show_coresize(struct module_attribute *mattr,
1063                              struct module_kobject *mk, char *buffer)
1064 {
1065         return sprintf(buffer, "%u\n", mk->mod->core_size);
1066 }
1067 
1068 static struct module_attribute modinfo_coresize =
1069         __ATTR(coresize, 0444, show_coresize, NULL);
1070 
1071 static ssize_t show_initsize(struct module_attribute *mattr,
1072                              struct module_kobject *mk, char *buffer)
1073 {
1074         return sprintf(buffer, "%u\n", mk->mod->init_size);
1075 }
1076 
1077 static struct module_attribute modinfo_initsize =
1078         __ATTR(initsize, 0444, show_initsize, NULL);
1079 
1080 static ssize_t show_taint(struct module_attribute *mattr,
1081                           struct module_kobject *mk, char *buffer)
1082 {
1083         size_t l;
1084 
1085         l = module_flags_taint(mk->mod, buffer);
1086         buffer[l++] = '\n';
1087         return l;
1088 }
1089 
1090 static struct module_attribute modinfo_taint =
1091         __ATTR(taint, 0444, show_taint, NULL);
1092 
1093 static struct module_attribute *modinfo_attrs[] = {
1094         &module_uevent,
1095         &modinfo_version,
1096         &modinfo_srcversion,
1097         &modinfo_initstate,
1098         &modinfo_coresize,
1099         &modinfo_initsize,
1100         &modinfo_taint,
1101 #ifdef CONFIG_MODULE_UNLOAD
1102         &modinfo_refcnt,
1103 #endif
1104         NULL,
1105 };
1106 
1107 static const char vermagic[] = VERMAGIC_STRING;
1108 
1109 static int try_to_force_load(struct module *mod, const char *reason)
1110 {
1111 #ifdef CONFIG_MODULE_FORCE_LOAD
1112         if (!test_taint(TAINT_FORCED_MODULE))
1113                 pr_warn("%s: %s: kernel tainted.\n", mod->name, reason);
1114         add_taint_module(mod, TAINT_FORCED_MODULE, LOCKDEP_NOW_UNRELIABLE);
1115         return 0;
1116 #else
1117         return -ENOEXEC;
1118 #endif
1119 }
1120 
1121 #ifdef CONFIG_MODVERSIONS
1122 /* If the arch applies (non-zero) relocations to kernel kcrctab, unapply it. */
1123 static unsigned long maybe_relocated(unsigned long crc,
1124                                      const struct module *crc_owner)
1125 {
1126 #ifdef ARCH_RELOCATES_KCRCTAB
1127         if (crc_owner == NULL)
1128                 return crc - (unsigned long)reloc_start;
1129 #endif
1130         return crc;
1131 }
1132 
1133 static int check_version(Elf_Shdr *sechdrs,
1134                          unsigned int versindex,
1135                          const char *symname,
1136                          struct module *mod, 
1137                          const unsigned long *crc,
1138                          const struct module *crc_owner)
1139 {
1140         unsigned int i, num_versions;
1141         struct modversion_info *versions;
1142 
1143         /* Exporting module didn't supply crcs?  OK, we're already tainted. */
1144         if (!crc)
1145                 return 1;
1146 
1147         /* No versions at all?  modprobe --force does this. */
1148         if (versindex == 0)
1149                 return try_to_force_load(mod, symname) == 0;
1150 
1151         versions = (void *) sechdrs[versindex].sh_addr;
1152         num_versions = sechdrs[versindex].sh_size
1153                 / sizeof(struct modversion_info);
1154 
1155         for (i = 0; i < num_versions; i++) {
1156                 if (strcmp(versions[i].name, symname) != 0)
1157                         continue;
1158 
1159                 if (versions[i].crc == maybe_relocated(*crc, crc_owner))
1160                         return 1;
1161                 pr_debug("Found checksum %lX vs module %lX\n",
1162                        maybe_relocated(*crc, crc_owner), versions[i].crc);
1163                 goto bad_version;
1164         }
1165 
1166         pr_warn("%s: no symbol version for %s\n", mod->name, symname);
1167         return 0;
1168 
1169 bad_version:
1170         printk("%s: disagrees about version of symbol %s\n",
1171                mod->name, symname);
1172         return 0;
1173 }
1174 
1175 static inline int check_modstruct_version(Elf_Shdr *sechdrs,
1176                                           unsigned int versindex,
1177                                           struct module *mod)
1178 {
1179         const unsigned long *crc;
1180 
1181         /* Since this should be found in kernel (which can't be removed),
1182          * no locking is necessary. */
1183         if (!find_symbol(VMLINUX_SYMBOL_STR(module_layout), NULL,
1184                          &crc, true, false))
1185                 BUG();
1186         return check_version(sechdrs, versindex,
1187                              VMLINUX_SYMBOL_STR(module_layout), mod, crc,
1188                              NULL);
1189 }
1190 
1191 /* First part is kernel version, which we ignore if module has crcs. */
1192 static inline int same_magic(const char *amagic, const char *bmagic,
1193                              bool has_crcs)
1194 {
1195         if (has_crcs) {
1196                 amagic += strcspn(amagic, " ");
1197                 bmagic += strcspn(bmagic, " ");
1198         }
1199         return strcmp(amagic, bmagic) == 0;
1200 }
1201 #else
1202 static inline int check_version(Elf_Shdr *sechdrs,
1203                                 unsigned int versindex,
1204                                 const char *symname,
1205                                 struct module *mod, 
1206                                 const unsigned long *crc,
1207                                 const struct module *crc_owner)
1208 {
1209         return 1;
1210 }
1211 
1212 static inline int check_modstruct_version(Elf_Shdr *sechdrs,
1213                                           unsigned int versindex,
1214                                           struct module *mod)
1215 {
1216         return 1;
1217 }
1218 
1219 static inline int same_magic(const char *amagic, const char *bmagic,
1220                              bool has_crcs)
1221 {
1222         return strcmp(amagic, bmagic) == 0;
1223 }
1224 #endif /* CONFIG_MODVERSIONS */
1225 
1226 /* Resolve a symbol for this module.  I.e. if we find one, record usage. */
1227 static const struct kernel_symbol *resolve_symbol(struct module *mod,
1228                                                   const struct load_info *info,
1229                                                   const char *name,
1230                                                   char ownername[])
1231 {
1232         struct module *owner;
1233         const struct kernel_symbol *sym;
1234         const unsigned long *crc;
1235         int err;
1236 
1237         mutex_lock(&module_mutex);
1238         sym = find_symbol(name, &owner, &crc,
1239                           !(mod->taints & (1 << TAINT_PROPRIETARY_MODULE)), true);
1240         if (!sym)
1241                 goto unlock;
1242 
1243         if (!check_version(info->sechdrs, info->index.vers, name, mod, crc,
1244                            owner)) {
1245                 sym = ERR_PTR(-EINVAL);
1246                 goto getname;
1247         }
1248 
1249         err = ref_module(mod, owner);
1250         if (err) {
1251                 sym = ERR_PTR(err);
1252                 goto getname;
1253         }
1254 
1255 getname:
1256         /* We must make copy under the lock if we failed to get ref. */
1257         strncpy(ownername, module_name(owner), MODULE_NAME_LEN);
1258 unlock:
1259         mutex_unlock(&module_mutex);
1260         return sym;
1261 }
1262 
1263 static const struct kernel_symbol *
1264 resolve_symbol_wait(struct module *mod,
1265                     const struct load_info *info,
1266                     const char *name)
1267 {
1268         const struct kernel_symbol *ksym;
1269         char owner[MODULE_NAME_LEN];
1270 
1271         if (wait_event_interruptible_timeout(module_wq,
1272                         !IS_ERR(ksym = resolve_symbol(mod, info, name, owner))
1273                         || PTR_ERR(ksym) != -EBUSY,
1274                                              30 * HZ) <= 0) {
1275                 pr_warn("%s: gave up waiting for init of module %s.\n",
1276                         mod->name, owner);
1277         }
1278         return ksym;
1279 }
1280 
1281 /*
1282  * /sys/module/foo/sections stuff
1283  * J. Corbet <corbet@lwn.net>
1284  */
1285 #ifdef CONFIG_SYSFS
1286 
1287 #ifdef CONFIG_KALLSYMS
1288 static inline bool sect_empty(const Elf_Shdr *sect)
1289 {
1290         return !(sect->sh_flags & SHF_ALLOC) || sect->sh_size == 0;
1291 }
1292 
1293 struct module_sect_attr
1294 {
1295         struct module_attribute mattr;
1296         char *name;
1297         unsigned long address;
1298 };
1299 
1300 struct module_sect_attrs
1301 {
1302         struct attribute_group grp;
1303         unsigned int nsections;
1304         struct module_sect_attr attrs[0];
1305 };
1306 
1307 static ssize_t module_sect_show(struct module_attribute *mattr,
1308                                 struct module_kobject *mk, char *buf)
1309 {
1310         struct module_sect_attr *sattr =
1311                 container_of(mattr, struct module_sect_attr, mattr);
1312         return sprintf(buf, "0x%pK\n", (void *)sattr->address);
1313 }
1314 
1315 static void free_sect_attrs(struct module_sect_attrs *sect_attrs)
1316 {
1317         unsigned int section;
1318 
1319         for (section = 0; section < sect_attrs->nsections; section++)
1320                 kfree(sect_attrs->attrs[section].name);
1321         kfree(sect_attrs);
1322 }
1323 
1324 static void add_sect_attrs(struct module *mod, const struct load_info *info)
1325 {
1326         unsigned int nloaded = 0, i, size[2];
1327         struct module_sect_attrs *sect_attrs;
1328         struct module_sect_attr *sattr;
1329         struct attribute **gattr;
1330 
1331         /* Count loaded sections and allocate structures */
1332         for (i = 0; i < info->hdr->e_shnum; i++)
1333                 if (!sect_empty(&info->sechdrs[i]))
1334                         nloaded++;
1335         size[0] = ALIGN(sizeof(*sect_attrs)
1336                         + nloaded * sizeof(sect_attrs->attrs[0]),
1337                         sizeof(sect_attrs->grp.attrs[0]));
1338         size[1] = (nloaded + 1) * sizeof(sect_attrs->grp.attrs[0]);
1339         sect_attrs = kzalloc(size[0] + size[1], GFP_KERNEL);
1340         if (sect_attrs == NULL)
1341                 return;
1342 
1343         /* Setup section attributes. */
1344         sect_attrs->grp.name = "sections";
1345         sect_attrs->grp.attrs = (void *)sect_attrs + size[0];
1346 
1347         sect_attrs->nsections = 0;
1348         sattr = &sect_attrs->attrs[0];
1349         gattr = &sect_attrs->grp.attrs[0];
1350         for (i = 0; i < info->hdr->e_shnum; i++) {
1351                 Elf_Shdr *sec = &info->sechdrs[i];
1352                 if (sect_empty(sec))
1353                         continue;
1354                 sattr->address = sec->sh_addr;
1355                 sattr->name = kstrdup(info->secstrings + sec->sh_name,
1356                                         GFP_KERNEL);
1357                 if (sattr->name == NULL)
1358                         goto out;
1359                 sect_attrs->nsections++;
1360                 sysfs_attr_init(&sattr->mattr.attr);
1361                 sattr->mattr.show = module_sect_show;
1362                 sattr->mattr.store = NULL;
1363                 sattr->mattr.attr.name = sattr->name;
1364                 sattr->mattr.attr.mode = S_IRUGO;
1365                 *(gattr++) = &(sattr++)->mattr.attr;
1366         }
1367         *gattr = NULL;
1368 
1369         if (sysfs_create_group(&mod->mkobj.kobj, &sect_attrs->grp))
1370                 goto out;
1371 
1372         mod->sect_attrs = sect_attrs;
1373         return;
1374   out:
1375         free_sect_attrs(sect_attrs);
1376 }
1377 
1378 static void remove_sect_attrs(struct module *mod)
1379 {
1380         if (mod->sect_attrs) {
1381                 sysfs_remove_group(&mod->mkobj.kobj,
1382                                    &mod->sect_attrs->grp);
1383                 /* We are positive that no one is using any sect attrs
1384                  * at this point.  Deallocate immediately. */
1385                 free_sect_attrs(mod->sect_attrs);
1386                 mod->sect_attrs = NULL;
1387         }
1388 }
1389 
1390 /*
1391  * /sys/module/foo/notes/.section.name gives contents of SHT_NOTE sections.
1392  */
1393 
1394 struct module_notes_attrs {
1395         struct kobject *dir;
1396         unsigned int notes;
1397         struct bin_attribute attrs[0];
1398 };
1399 
1400 static ssize_t module_notes_read(struct file *filp, struct kobject *kobj,
1401                                  struct bin_attribute *bin_attr,
1402                                  char *buf, loff_t pos, size_t count)
1403 {
1404         /*
1405          * The caller checked the pos and count against our size.
1406          */
1407         memcpy(buf, bin_attr->private + pos, count);
1408         return count;
1409 }
1410 
1411 static void free_notes_attrs(struct module_notes_attrs *notes_attrs,
1412                              unsigned int i)
1413 {
1414         if (notes_attrs->dir) {
1415                 while (i-- > 0)
1416                         sysfs_remove_bin_file(notes_attrs->dir,
1417                                               &notes_attrs->attrs[i]);
1418                 kobject_put(notes_attrs->dir);
1419         }
1420         kfree(notes_attrs);
1421 }
1422 
1423 static void add_notes_attrs(struct module *mod, const struct load_info *info)
1424 {
1425         unsigned int notes, loaded, i;
1426         struct module_notes_attrs *notes_attrs;
1427         struct bin_attribute *nattr;
1428 
1429         /* failed to create section attributes, so can't create notes */
1430         if (!mod->sect_attrs)
1431                 return;
1432 
1433         /* Count notes sections and allocate structures.  */
1434         notes = 0;
1435         for (i = 0; i < info->hdr->e_shnum; i++)
1436                 if (!sect_empty(&info->sechdrs[i]) &&
1437                     (info->sechdrs[i].sh_type == SHT_NOTE))
1438                         ++notes;
1439 
1440         if (notes == 0)
1441                 return;
1442 
1443         notes_attrs = kzalloc(sizeof(*notes_attrs)
1444                               + notes * sizeof(notes_attrs->attrs[0]),
1445                               GFP_KERNEL);
1446         if (notes_attrs == NULL)
1447                 return;
1448 
1449         notes_attrs->notes = notes;
1450         nattr = &notes_attrs->attrs[0];
1451         for (loaded = i = 0; i < info->hdr->e_shnum; ++i) {
1452                 if (sect_empty(&info->sechdrs[i]))
1453                         continue;
1454                 if (info->sechdrs[i].sh_type == SHT_NOTE) {
1455                         sysfs_bin_attr_init(nattr);
1456                         nattr->attr.name = mod->sect_attrs->attrs[loaded].name;
1457                         nattr->attr.mode = S_IRUGO;
1458                         nattr->size = info->sechdrs[i].sh_size;
1459                         nattr->private = (void *) info->sechdrs[i].sh_addr;
1460                         nattr->read = module_notes_read;
1461                         ++nattr;
1462                 }
1463                 ++loaded;
1464         }
1465 
1466         notes_attrs->dir = kobject_create_and_add("notes", &mod->mkobj.kobj);
1467         if (!notes_attrs->dir)
1468                 goto out;
1469 
1470         for (i = 0; i < notes; ++i)
1471                 if (sysfs_create_bin_file(notes_attrs->dir,
1472                                           &notes_attrs->attrs[i]))
1473                         goto out;
1474 
1475         mod->notes_attrs = notes_attrs;
1476         return;
1477 
1478   out:
1479         free_notes_attrs(notes_attrs, i);
1480 }
1481 
1482 static void remove_notes_attrs(struct module *mod)
1483 {
1484         if (mod->notes_attrs)
1485                 free_notes_attrs(mod->notes_attrs, mod->notes_attrs->notes);
1486 }
1487 
1488 #else
1489 
1490 static inline void add_sect_attrs(struct module *mod,
1491                                   const struct load_info *info)
1492 {
1493 }
1494 
1495 static inline void remove_sect_attrs(struct module *mod)
1496 {
1497 }
1498 
1499 static inline void add_notes_attrs(struct module *mod,
1500                                    const struct load_info *info)
1501 {
1502 }
1503 
1504 static inline void remove_notes_attrs(struct module *mod)
1505 {
1506 }
1507 #endif /* CONFIG_KALLSYMS */
1508 
1509 static void add_usage_links(struct module *mod)
1510 {
1511 #ifdef CONFIG_MODULE_UNLOAD
1512         struct module_use *use;
1513         int nowarn;
1514 
1515         mutex_lock(&module_mutex);
1516         list_for_each_entry(use, &mod->target_list, target_list) {
1517                 nowarn = sysfs_create_link(use->target->holders_dir,
1518                                            &mod->mkobj.kobj, mod->name);
1519         }
1520         mutex_unlock(&module_mutex);
1521 #endif
1522 }
1523 
1524 static void del_usage_links(struct module *mod)
1525 {
1526 #ifdef CONFIG_MODULE_UNLOAD
1527         struct module_use *use;
1528 
1529         mutex_lock(&module_mutex);
1530         list_for_each_entry(use, &mod->target_list, target_list)
1531                 sysfs_remove_link(use->target->holders_dir, mod->name);
1532         mutex_unlock(&module_mutex);
1533 #endif
1534 }
1535 
1536 static int module_add_modinfo_attrs(struct module *mod)
1537 {
1538         struct module_attribute *attr;
1539         struct module_attribute *temp_attr;
1540         int error = 0;
1541         int i;
1542 
1543         mod->modinfo_attrs = kzalloc((sizeof(struct module_attribute) *
1544                                         (ARRAY_SIZE(modinfo_attrs) + 1)),
1545                                         GFP_KERNEL);
1546         if (!mod->modinfo_attrs)
1547                 return -ENOMEM;
1548 
1549         temp_attr = mod->modinfo_attrs;
1550         for (i = 0; (attr = modinfo_attrs[i]) && !error; i++) {
1551                 if (!attr->test ||
1552                     (attr->test && attr->test(mod))) {
1553                         memcpy(temp_attr, attr, sizeof(*temp_attr));
1554                         sysfs_attr_init(&temp_attr->attr);
1555                         error = sysfs_create_file(&mod->mkobj.kobj,&temp_attr->attr);
1556                         ++temp_attr;
1557                 }
1558         }
1559         return error;
1560 }
1561 
1562 static void module_remove_modinfo_attrs(struct module *mod)
1563 {
1564         struct module_attribute *attr;
1565         int i;
1566 
1567         for (i = 0; (attr = &mod->modinfo_attrs[i]); i++) {
1568                 /* pick a field to test for end of list */
1569                 if (!attr->attr.name)
1570                         break;
1571                 sysfs_remove_file(&mod->mkobj.kobj,&attr->attr);
1572                 if (attr->free)
1573                         attr->free(mod);
1574         }
1575         kfree(mod->modinfo_attrs);
1576 }
1577 
1578 static void mod_kobject_put(struct module *mod)
1579 {
1580         DECLARE_COMPLETION_ONSTACK(c);
1581         mod->mkobj.kobj_completion = &c;
1582         kobject_put(&mod->mkobj.kobj);
1583         wait_for_completion(&c);
1584 }
1585 
1586 static int mod_sysfs_init(struct module *mod)
1587 {
1588         int err;
1589         struct kobject *kobj;
1590 
1591         if (!module_sysfs_initialized) {
1592                 pr_err("%s: module sysfs not initialized\n", mod->name);
1593                 err = -EINVAL;
1594                 goto out;
1595         }
1596 
1597         kobj = kset_find_obj(module_kset, mod->name);
1598         if (kobj) {
1599                 pr_err("%s: module is already loaded\n", mod->name);
1600                 kobject_put(kobj);
1601                 err = -EINVAL;
1602                 goto out;
1603         }
1604 
1605         mod->mkobj.mod = mod;
1606 
1607         memset(&mod->mkobj.kobj, 0, sizeof(mod->mkobj.kobj));
1608         mod->mkobj.kobj.kset = module_kset;
1609         err = kobject_init_and_add(&mod->mkobj.kobj, &module_ktype, NULL,
1610                                    "%s", mod->name);
1611         if (err)
1612                 mod_kobject_put(mod);
1613 
1614         /* delay uevent until full sysfs population */
1615 out:
1616         return err;
1617 }
1618 
1619 static int mod_sysfs_setup(struct module *mod,
1620                            const struct load_info *info,
1621                            struct kernel_param *kparam,
1622                            unsigned int num_params)
1623 {
1624         int err;
1625 
1626         err = mod_sysfs_init(mod);
1627         if (err)
1628                 goto out;
1629 
1630         mod->holders_dir = kobject_create_and_add("holders", &mod->mkobj.kobj);
1631         if (!mod->holders_dir) {
1632                 err = -ENOMEM;
1633                 goto out_unreg;
1634         }
1635 
1636         err = module_param_sysfs_setup(mod, kparam, num_params);
1637         if (err)
1638                 goto out_unreg_holders;
1639 
1640         err = module_add_modinfo_attrs(mod);
1641         if (err)
1642                 goto out_unreg_param;
1643 
1644         add_usage_links(mod);
1645         add_sect_attrs(mod, info);
1646         add_notes_attrs(mod, info);
1647 
1648         kobject_uevent(&mod->mkobj.kobj, KOBJ_ADD);
1649         return 0;
1650 
1651 out_unreg_param:
1652         module_param_sysfs_remove(mod);
1653 out_unreg_holders:
1654         kobject_put(mod->holders_dir);
1655 out_unreg:
1656         mod_kobject_put(mod);
1657 out:
1658         return err;
1659 }
1660 
1661 static void mod_sysfs_fini(struct module *mod)
1662 {
1663         remove_notes_attrs(mod);
1664         remove_sect_attrs(mod);
1665         mod_kobject_put(mod);
1666 }
1667 
1668 #else /* !CONFIG_SYSFS */
1669 
1670 static int mod_sysfs_setup(struct module *mod,
1671                            const struct load_info *info,
1672                            struct kernel_param *kparam,
1673                            unsigned int num_params)
1674 {
1675         return 0;
1676 }
1677 
1678 static void mod_sysfs_fini(struct module *mod)
1679 {
1680 }
1681 
1682 static void module_remove_modinfo_attrs(struct module *mod)
1683 {
1684 }
1685 
1686 static void del_usage_links(struct module *mod)
1687 {
1688 }
1689 
1690 #endif /* CONFIG_SYSFS */
1691 
1692 static void mod_sysfs_teardown(struct module *mod)
1693 {
1694         del_usage_links(mod);
1695         module_remove_modinfo_attrs(mod);
1696         module_param_sysfs_remove(mod);
1697         kobject_put(mod->mkobj.drivers_dir);
1698         kobject_put(mod->holders_dir);
1699         mod_sysfs_fini(mod);
1700 }
1701 
1702 /*
1703  * unlink the module with the whole machine is stopped with interrupts off
1704  * - this defends against kallsyms not taking locks
1705  */
1706 static int __unlink_module(void *_mod)
1707 {
1708         struct module *mod = _mod;
1709         list_del(&mod->list);
1710         module_bug_cleanup(mod);
1711         return 0;
1712 }
1713 
1714 #ifdef CONFIG_DEBUG_SET_MODULE_RONX
1715 /*
1716  * LKM RO/NX protection: protect module's text/ro-data
1717  * from modification and any data from execution.
1718  */
1719 void set_page_attributes(void *start, void *end, int (*set)(unsigned long start, int num_pages))
1720 {
1721         unsigned long begin_pfn = PFN_DOWN((unsigned long)start);
1722         unsigned long end_pfn = PFN_DOWN((unsigned long)end);
1723 
1724         if (end_pfn > begin_pfn)
1725                 set(begin_pfn << PAGE_SHIFT, end_pfn - begin_pfn);
1726 }
1727 
1728 static void set_section_ro_nx(void *base,
1729                         unsigned long text_size,
1730                         unsigned long ro_size,
1731                         unsigned long total_size)
1732 {
1733         /* begin and end PFNs of the current subsection */
1734         unsigned long begin_pfn;
1735         unsigned long end_pfn;
1736 
1737         /*
1738          * Set RO for module text and RO-data:
1739          * - Always protect first page.
1740          * - Do not protect last partial page.
1741          */
1742         if (ro_size > 0)
1743                 set_page_attributes(base, base + ro_size, set_memory_ro);
1744 
1745         /*
1746          * Set NX permissions for module data:
1747          * - Do not protect first partial page.
1748          * - Always protect last page.
1749          */
1750         if (total_size > text_size) {
1751                 begin_pfn = PFN_UP((unsigned long)base + text_size);
1752                 end_pfn = PFN_UP((unsigned long)base + total_size);
1753                 if (end_pfn > begin_pfn)
1754                         set_memory_nx(begin_pfn << PAGE_SHIFT, end_pfn - begin_pfn);
1755         }
1756 }
1757 
1758 static void unset_module_core_ro_nx(struct module *mod)
1759 {
1760         set_page_attributes(mod->module_core + mod->core_text_size,
1761                 mod->module_core + mod->core_size,
1762                 set_memory_x);
1763         set_page_attributes(mod->module_core,
1764                 mod->module_core + mod->core_ro_size,
1765                 set_memory_rw);
1766 }
1767 
1768 static void unset_module_init_ro_nx(struct module *mod)
1769 {
1770         set_page_attributes(mod->module_init + mod->init_text_size,
1771                 mod->module_init + mod->init_size,
1772                 set_memory_x);
1773         set_page_attributes(mod->module_init,
1774                 mod->module_init + mod->init_ro_size,
1775                 set_memory_rw);
1776 }
1777 
1778 /* Iterate through all modules and set each module's text as RW */
1779 void set_all_modules_text_rw(void)
1780 {
1781         struct module *mod;
1782 
1783         mutex_lock(&module_mutex);
1784         list_for_each_entry_rcu(mod, &modules, list) {
1785                 if (mod->state == MODULE_STATE_UNFORMED)
1786                         continue;
1787                 if ((mod->module_core) && (mod->core_text_size)) {
1788                         set_page_attributes(mod->module_core,
1789                                                 mod->module_core + mod->core_text_size,
1790                                                 set_memory_rw);
1791                 }
1792                 if ((mod->module_init) && (mod->init_text_size)) {
1793                         set_page_attributes(mod->module_init,
1794                                                 mod->module_init + mod->init_text_size,
1795                                                 set_memory_rw);
1796                 }
1797         }
1798         mutex_unlock(&module_mutex);
1799 }
1800 
1801 /* Iterate through all modules and set each module's text as RO */
1802 void set_all_modules_text_ro(void)
1803 {
1804         struct module *mod;
1805 
1806         mutex_lock(&module_mutex);
1807         list_for_each_entry_rcu(mod, &modules, list) {
1808                 if (mod->state == MODULE_STATE_UNFORMED)
1809                         continue;
1810                 if ((mod->module_core) && (mod->core_text_size)) {
1811                         set_page_attributes(mod->module_core,
1812                                                 mod->module_core + mod->core_text_size,
1813                                                 set_memory_ro);
1814                 }
1815                 if ((mod->module_init) && (mod->init_text_size)) {
1816                         set_page_attributes(mod->module_init,
1817                                                 mod->module_init + mod->init_text_size,
1818                                                 set_memory_ro);
1819                 }
1820         }
1821         mutex_unlock(&module_mutex);
1822 }
1823 #else
1824 static inline void set_section_ro_nx(void *base, unsigned long text_size, unsigned long ro_size, unsigned long total_size) { }
1825 static void unset_module_core_ro_nx(struct module *mod) { }
1826 static void unset_module_init_ro_nx(struct module *mod) { }
1827 #endif
1828 
1829 void __weak module_free(struct module *mod, void *module_region)
1830 {
1831         vfree(module_region);
1832 }
1833 
1834 void __weak module_arch_cleanup(struct module *mod)
1835 {
1836 }
1837 
1838 /* Free a module, remove from lists, etc. */
1839 static void free_module(struct module *mod)
1840 {
1841         trace_module_free(mod);
1842 
1843         mod_sysfs_teardown(mod);
1844 
1845         /* We leave it in list to prevent duplicate loads, but make sure
1846          * that noone uses it while it's being deconstructed. */
1847         mod->state = MODULE_STATE_UNFORMED;
1848 
1849         /* Remove dynamic debug info */
1850         ddebug_remove_module(mod->name);
1851 
1852         /* Arch-specific cleanup. */
1853         module_arch_cleanup(mod);
1854 
1855         /* Module unload stuff */
1856         module_unload_free(mod);
1857 
1858         /* Free any allocated parameters. */
1859         destroy_params(mod->kp, mod->num_kp);
1860 
1861         /* Now we can delete it from the lists */
1862         mutex_lock(&module_mutex);
1863         stop_machine(__unlink_module, mod, NULL);
1864         mutex_unlock(&module_mutex);
1865 
1866         /* This may be NULL, but that's OK */
1867         unset_module_init_ro_nx(mod);
1868         module_free(mod, mod->module_init);
1869         kfree(mod->args);
1870         percpu_modfree(mod);
1871 
1872         /* Free lock-classes: */
1873         lockdep_free_key_range(mod->module_core, mod->core_size);
1874 
1875         /* Finally, free the core (containing the module structure) */
1876         unset_module_core_ro_nx(mod);
1877         module_free(mod, mod->module_core);
1878 
1879 #ifdef CONFIG_MPU
1880         update_protections(current->mm);
1881 #endif
1882 }
1883 
1884 void *__symbol_get(const char *symbol)
1885 {
1886         struct module *owner;
1887         const struct kernel_symbol *sym;
1888 
1889         preempt_disable();
1890         sym = find_symbol(symbol, &owner, NULL, true, true);
1891         if (sym && strong_try_module_get(owner))
1892                 sym = NULL;
1893         preempt_enable();
1894 
1895         return sym ? (void *)sym->value : NULL;
1896 }
1897 EXPORT_SYMBOL_GPL(__symbol_get);
1898 
1899 /*
1900  * Ensure that an exported symbol [global namespace] does not already exist
1901  * in the kernel or in some other module's exported symbol table.
1902  *
1903  * You must hold the module_mutex.
1904  */
1905 static int verify_export_symbols(struct module *mod)
1906 {
1907         unsigned int i;
1908         struct module *owner;
1909         const struct kernel_symbol *s;
1910         struct {
1911                 const struct kernel_symbol *sym;
1912                 unsigned int num;
1913         } arr[] = {
1914                 { mod->syms, mod->num_syms },
1915                 { mod->gpl_syms, mod->num_gpl_syms },
1916                 { mod->gpl_future_syms, mod->num_gpl_future_syms },
1917 #ifdef CONFIG_UNUSED_SYMBOLS
1918                 { mod->unused_syms, mod->num_unused_syms },
1919                 { mod->unused_gpl_syms, mod->num_unused_gpl_syms },
1920 #endif
1921         };
1922 
1923         for (i = 0; i < ARRAY_SIZE(arr); i++) {
1924                 for (s = arr[i].sym; s < arr[i].sym + arr[i].num; s++) {
1925                         if (find_symbol(s->name, &owner, NULL, true, false)) {
1926                                 pr_err("%s: exports duplicate symbol %s"
1927                                        " (owned by %s)\n",
1928                                        mod->name, s->name, module_name(owner));
1929                                 return -ENOEXEC;
1930                         }
1931                 }
1932         }
1933         return 0;
1934 }
1935 
1936 /* Change all symbols so that st_value encodes the pointer directly. */
1937 static int simplify_symbols(struct module *mod, const struct load_info *info)
1938 {
1939         Elf_Shdr *symsec = &info->sechdrs[info->index.sym];
1940         Elf_Sym *sym = (void *)symsec->sh_addr;
1941         unsigned long secbase;
1942         unsigned int i;
1943         int ret = 0;
1944         const struct kernel_symbol *ksym;
1945 
1946         for (i = 1; i < symsec->sh_size / sizeof(Elf_Sym); i++) {
1947                 const char *name = info->strtab + sym[i].st_name;
1948 
1949                 switch (sym[i].st_shndx) {
1950                 case SHN_COMMON:
1951                         /* We compiled with -fno-common.  These are not
1952                            supposed to happen.  */
1953                         pr_debug("Common symbol: %s\n", name);
1954                         printk("%s: please compile with -fno-common\n",
1955                                mod->name);
1956                         ret = -ENOEXEC;
1957                         break;
1958 
1959                 case SHN_ABS:
1960                         /* Don't need to do anything */
1961                         pr_debug("Absolute symbol: 0x%08lx\n",
1962                                (long)sym[i].st_value);
1963                         break;
1964 
1965                 case SHN_UNDEF:
1966                         ksym = resolve_symbol_wait(mod, info, name);
1967                         /* Ok if resolved.  */
1968                         if (ksym && !IS_ERR(ksym)) {
1969                                 sym[i].st_value = ksym->value;
1970                                 break;
1971                         }
1972 
1973                         /* Ok if weak.  */
1974                         if (!ksym && ELF_ST_BIND(sym[i].st_info) == STB_WEAK)
1975                                 break;
1976 
1977                         pr_warn("%s: Unknown symbol %s (err %li)\n",
1978                                 mod->name, name, PTR_ERR(ksym));
1979                         ret = PTR_ERR(ksym) ?: -ENOENT;
1980                         break;
1981 
1982                 default:
1983                         /* Divert to percpu allocation if a percpu var. */
1984                         if (sym[i].st_shndx == info->index.pcpu)
1985                                 secbase = (unsigned long)mod_percpu(mod);
1986                         else
1987                                 secbase = info->sechdrs[sym[i].st_shndx].sh_addr;
1988                         sym[i].st_value += secbase;
1989                         break;
1990                 }
1991         }
1992 
1993         return ret;
1994 }
1995 
1996 static int apply_relocations(struct module *mod, const struct load_info *info)
1997 {
1998         unsigned int i;
1999         int err = 0;
2000 
2001         /* Now do relocations. */
2002         for (i = 1; i < info->hdr->e_shnum; i++) {
2003                 unsigned int infosec = info->sechdrs[i].sh_info;
2004 
2005                 /* Not a valid relocation section? */
2006                 if (infosec >= info->hdr->e_shnum)
2007                         continue;
2008 
2009                 /* Don't bother with non-allocated sections */
2010                 if (!(info->sechdrs[infosec].sh_flags & SHF_ALLOC))
2011                         continue;
2012 
2013                 if (info->sechdrs[i].sh_type == SHT_REL)
2014                         err = apply_relocate(info->sechdrs, info->strtab,
2015                                              info->index.sym, i, mod);
2016                 else if (info->sechdrs[i].sh_type == SHT_RELA)
2017                         err = apply_relocate_add(info->sechdrs, info->strtab,
2018                                                  info->index.sym, i, mod);
2019                 if (err < 0)
2020                         break;
2021         }
2022         return err;
2023 }
2024 
2025 /* Additional bytes needed by arch in front of individual sections */
2026 unsigned int __weak arch_mod_section_prepend(struct module *mod,
2027                                              unsigned int section)
2028 {
2029         /* default implementation just returns zero */
2030         return 0;
2031 }
2032 
2033 /* Update size with this section: return offset. */
2034 static long get_offset(struct module *mod, unsigned int *size,
2035                        Elf_Shdr *sechdr, unsigned int section)
2036 {
2037         long ret;
2038 
2039         *size += arch_mod_section_prepend(mod, section);
2040         ret = ALIGN(*size, sechdr->sh_addralign ?: 1);
2041         *size = ret + sechdr->sh_size;
2042         return ret;
2043 }
2044 
2045 /* Lay out the SHF_ALLOC sections in a way not dissimilar to how ld
2046    might -- code, read-only data, read-write data, small data.  Tally
2047    sizes, and place the offsets into sh_entsize fields: high bit means it
2048    belongs in init. */
2049 static void layout_sections(struct module *mod, struct load_info *info)
2050 {
2051         static unsigned long const masks[][2] = {
2052                 /* NOTE: all executable code must be the first section
2053                  * in this array; otherwise modify the text_size
2054                  * finder in the two loops below */
2055                 { SHF_EXECINSTR | SHF_ALLOC, ARCH_SHF_SMALL },
2056                 { SHF_ALLOC, SHF_WRITE | ARCH_SHF_SMALL },
2057                 { SHF_WRITE | SHF_ALLOC, ARCH_SHF_SMALL },
2058                 { ARCH_SHF_SMALL | SHF_ALLOC, 0 }
2059         };
2060         unsigned int m, i;
2061 
2062         for (i = 0; i < info->hdr->e_shnum; i++)
2063                 info->sechdrs[i].sh_entsize = ~0UL;
2064 
2065         pr_debug("Core section allocation order:\n");
2066         for (m = 0; m < ARRAY_SIZE(masks); ++m) {
2067                 for (i = 0; i < info->hdr->e_shnum; ++i) {
2068                         Elf_Shdr *s = &info->sechdrs[i];
2069                         const char *sname = info->secstrings + s->sh_name;
2070 
2071                         if ((s->sh_flags & masks[m][0]) != masks[m][0]
2072                             || (s->sh_flags & masks[m][1])
2073                             || s->sh_entsize != ~0UL
2074                             || strstarts(sname, ".init"))
2075                                 continue;
2076                         s->sh_entsize = get_offset(mod, &mod->core_size, s, i);
2077                         pr_debug("\t%s\n", sname);
2078                 }
2079                 switch (m) {
2080                 case 0: /* executable */
2081                         mod->core_size = debug_align(mod->core_size);
2082                         mod->core_text_size = mod->core_size;
2083                         break;
2084                 case 1: /* RO: text and ro-data */
2085                         mod->core_size = debug_align(mod->core_size);
2086                         mod->core_ro_size = mod->core_size;
2087                         break;
2088                 case 3: /* whole core */
2089                         mod->core_size = debug_align(mod->core_size);
2090                         break;
2091                 }
2092         }
2093 
2094         pr_debug("Init section allocation order:\n");
2095         for (m = 0; m < ARRAY_SIZE(masks); ++m) {
2096                 for (i = 0; i < info->hdr->e_shnum; ++i) {
2097                         Elf_Shdr *s = &info->sechdrs[i];
2098                         const char *sname = info->secstrings + s->sh_name;
2099 
2100                         if ((s->sh_flags & masks[m][0]) != masks[m][0]
2101                             || (s->sh_flags & masks[m][1])
2102                             || s->sh_entsize != ~0UL
2103                             || !strstarts(sname, ".init"))
2104                                 continue;
2105                         s->sh_entsize = (get_offset(mod, &mod->init_size, s, i)
2106                                          | INIT_OFFSET_MASK);
2107                         pr_debug("\t%s\n", sname);
2108                 }
2109                 switch (m) {
2110                 case 0: /* executable */
2111                         mod->init_size = debug_align(mod->init_size);
2112                         mod->init_text_size = mod->init_size;
2113                         break;
2114                 case 1: /* RO: text and ro-data */
2115                         mod->init_size = debug_align(mod->init_size);
2116                         mod->init_ro_size = mod->init_size;
2117                         break;
2118                 case 3: /* whole init */
2119                         mod->init_size = debug_align(mod->init_size);
2120                         break;
2121                 }
2122         }
2123 }
2124 
2125 static void set_license(struct module *mod, const char *license)
2126 {
2127         if (!license)
2128                 license = "unspecified";
2129 
2130         if (!license_is_gpl_compatible(license)) {
2131                 if (!test_taint(TAINT_PROPRIETARY_MODULE))
2132                         pr_warn("%s: module license '%s' taints kernel.\n",
2133                                 mod->name, license);
2134                 add_taint_module(mod, TAINT_PROPRIETARY_MODULE,
2135                                  LOCKDEP_NOW_UNRELIABLE);
2136         }
2137 }
2138 
2139 /* Parse tag=value strings from .modinfo section */
2140 static char *next_string(char *string, unsigned long *secsize)
2141 {
2142         /* Skip non-zero chars */
2143         while (string[0]) {
2144                 string++;
2145                 if ((*secsize)-- <= 1)
2146                         return NULL;
2147         }
2148 
2149         /* Skip any zero padding. */
2150         while (!string[0]) {
2151                 string++;
2152                 if ((*secsize)-- <= 1)
2153                         return NULL;
2154         }
2155         return string;
2156 }
2157 
2158 static char *get_modinfo(struct load_info *info, const char *tag)
2159 {
2160         char *p;
2161         unsigned int taglen = strlen(tag);
2162         Elf_Shdr *infosec = &info->sechdrs[info->index.info];
2163         unsigned long size = infosec->sh_size;
2164 
2165         for (p = (char *)infosec->sh_addr; p; p = next_string(p, &size)) {
2166                 if (strncmp(p, tag, taglen) == 0 && p[taglen] == '=')
2167                         return p + taglen + 1;
2168         }
2169         return NULL;
2170 }
2171 
2172 static void setup_modinfo(struct module *mod, struct load_info *info)
2173 {
2174         struct module_attribute *attr;
2175         int i;
2176 
2177         for (i = 0; (attr = modinfo_attrs[i]); i++) {
2178                 if (attr->setup)
2179                         attr->setup(mod, get_modinfo(info, attr->attr.name));
2180         }
2181 }
2182 
2183 static void free_modinfo(struct module *mod)
2184 {
2185         struct module_attribute *attr;
2186         int i;
2187 
2188         for (i = 0; (attr = modinfo_attrs[i]); i++) {
2189                 if (attr->free)
2190                         attr->free(mod);
2191         }
2192 }
2193 
2194 #ifdef CONFIG_KALLSYMS
2195 
2196 /* lookup symbol in given range of kernel_symbols */
2197 static const struct kernel_symbol *lookup_symbol(const char *name,
2198         const struct kernel_symbol *start,
2199         const struct kernel_symbol *stop)
2200 {
2201         return bsearch(name, start, stop - start,
2202                         sizeof(struct kernel_symbol), cmp_name);
2203 }
2204 
2205 static int is_exported(const char *name, unsigned long value,
2206                        const struct module *mod)
2207 {
2208         const struct kernel_symbol *ks;
2209         if (!mod)
2210                 ks = lookup_symbol(name, __start___ksymtab, __stop___ksymtab);
2211         else
2212                 ks = lookup_symbol(name, mod->syms, mod->syms + mod->num_syms);
2213         return ks != NULL && ks->value == value;
2214 }
2215 
2216 /* As per nm */
2217 static char elf_type(const Elf_Sym *sym, const struct load_info *info)
2218 {
2219         const Elf_Shdr *sechdrs = info->sechdrs;
2220 
2221         if (ELF_ST_BIND(sym->st_info) == STB_WEAK) {
2222                 if (ELF_ST_TYPE(sym->st_info) == STT_OBJECT)
2223                         return 'v';
2224                 else
2225                         return 'w';
2226         }
2227         if (sym->st_shndx == SHN_UNDEF)
2228                 return 'U';
2229         if (sym->st_shndx == SHN_ABS)
2230                 return 'a';
2231         if (sym->st_shndx >= SHN_LORESERVE)
2232                 return '?';
2233         if (sechdrs[sym->st_shndx].sh_flags & SHF_EXECINSTR)
2234                 return 't';
2235         if (sechdrs[sym->st_shndx].sh_flags & SHF_ALLOC
2236             && sechdrs[sym->st_shndx].sh_type != SHT_NOBITS) {
2237                 if (!(sechdrs[sym->st_shndx].sh_flags & SHF_WRITE))
2238                         return 'r';
2239                 else if (sechdrs[sym->st_shndx].sh_flags & ARCH_SHF_SMALL)
2240                         return 'g';
2241                 else
2242                         return 'd';
2243         }
2244         if (sechdrs[sym->st_shndx].sh_type == SHT_NOBITS) {
2245                 if (sechdrs[sym->st_shndx].sh_flags & ARCH_SHF_SMALL)
2246                         return 's';
2247                 else
2248                         return 'b';
2249         }
2250         if (strstarts(info->secstrings + sechdrs[sym->st_shndx].sh_name,
2251                       ".debug")) {
2252                 return 'n';
2253         }
2254         return '?';
2255 }
2256 
2257 static bool is_core_symbol(const Elf_Sym *src, const Elf_Shdr *sechdrs,
2258                            unsigned int shnum)
2259 {
2260         const Elf_Shdr *sec;
2261 
2262         if (src->st_shndx == SHN_UNDEF
2263             || src->st_shndx >= shnum
2264             || !src->st_name)
2265                 return false;
2266 
2267         sec = sechdrs + src->st_shndx;
2268         if (!(sec->sh_flags & SHF_ALLOC)
2269 #ifndef CONFIG_KALLSYMS_ALL
2270             || !(sec->sh_flags & SHF_EXECINSTR)
2271 #endif
2272             || (sec->sh_entsize & INIT_OFFSET_MASK))
2273                 return false;
2274 
2275         return true;
2276 }
2277 
2278 /*
2279  * We only allocate and copy the strings needed by the parts of symtab
2280  * we keep.  This is simple, but has the effect of making multiple
2281  * copies of duplicates.  We could be more sophisticated, see
2282  * linux-kernel thread starting with
2283  * <73defb5e4bca04a6431392cc341112b1@localhost>.
2284  */
2285 static void layout_symtab(struct module *mod, struct load_info *info)
2286 {
2287         Elf_Shdr *symsect = info->sechdrs + info->index.sym;
2288         Elf_Shdr *strsect = info->sechdrs + info->index.str;
2289         const Elf_Sym *src;
2290         unsigned int i, nsrc, ndst, strtab_size = 0;
2291 
2292         /* Put symbol section at end of init part of module. */
2293         symsect->sh_flags |= SHF_ALLOC;
2294         symsect->sh_entsize = get_offset(mod, &mod->init_size, symsect,
2295                                          info->index.sym) | INIT_OFFSET_MASK;
2296         pr_debug("\t%s\n", info->secstrings + symsect->sh_name);
2297 
2298         src = (void *)info->hdr + symsect->sh_offset;
2299         nsrc = symsect->sh_size / sizeof(*src);
2300 
2301         /* Compute total space required for the core symbols' strtab. */
2302         for (ndst = i = 0; i < nsrc; i++) {
2303                 if (i == 0 ||
2304                     is_core_symbol(src+i, info->sechdrs, info->hdr->e_shnum)) {
2305                         strtab_size += strlen(&info->strtab[src[i].st_name])+1;
2306                         ndst++;
2307                 }
2308         }
2309 
2310         /* Append room for core symbols at end of core part. */
2311         info->symoffs = ALIGN(mod->core_size, symsect->sh_addralign ?: 1);
2312         info->stroffs = mod->core_size = info->symoffs + ndst * sizeof(Elf_Sym);
2313         mod->core_size += strtab_size;
2314 
2315         /* Put string table section at end of init part of module. */
2316         strsect->sh_flags |= SHF_ALLOC;
2317         strsect->sh_entsize = get_offset(mod, &mod->init_size, strsect,
2318                                          info->index.str) | INIT_OFFSET_MASK;
2319         pr_debug("\t%s\n", info->secstrings + strsect->sh_name);
2320 }
2321 
2322 static void add_kallsyms(struct module *mod, const struct load_info *info)
2323 {
2324         unsigned int i, ndst;
2325         const Elf_Sym *src;
2326         Elf_Sym *dst;
2327         char *s;
2328         Elf_Shdr *symsec = &info->sechdrs[info->index.sym];
2329 
2330         mod->symtab = (void *)symsec->sh_addr;
2331         mod->num_symtab = symsec->sh_size / sizeof(Elf_Sym);
2332         /* Make sure we get permanent strtab: don't use info->strtab. */
2333         mod->strtab = (void *)info->sechdrs[info->index.str].sh_addr;
2334 
2335         /* Set types up while we still have access to sections. */
2336         for (i = 0; i < mod->num_symtab; i++)
2337                 mod->symtab[i].st_info = elf_type(&mod->symtab[i], info);
2338 
2339         mod->core_symtab = dst = mod->module_core + info->symoffs;
2340         mod->core_strtab = s = mod->module_core + info->stroffs;
2341         src = mod->symtab;
2342         for (ndst = i = 0; i < mod->num_symtab; i++) {
2343                 if (i == 0 ||
2344                     is_core_symbol(src+i, info->sechdrs, info->hdr->e_shnum)) {
2345                         dst[ndst] = src[i];
2346                         dst[ndst++].st_name = s - mod->core_strtab;
2347                         s += strlcpy(s, &mod->strtab[src[i].st_name],
2348                                      KSYM_NAME_LEN) + 1;
2349                 }
2350         }
2351         mod->core_num_syms = ndst;
2352 }
2353 #else
2354 static inline void layout_symtab(struct module *mod, struct load_info *info)
2355 {
2356 }
2357 
2358 static void add_kallsyms(struct module *mod, const struct load_info *info)
2359 {
2360 }
2361 #endif /* CONFIG_KALLSYMS */
2362 
2363 static void dynamic_debug_setup(struct _ddebug *debug, unsigned int num)
2364 {
2365         if (!debug)
2366                 return;
2367 #ifdef CONFIG_DYNAMIC_DEBUG
2368         if (ddebug_add_module(debug, num, debug->modname))
2369                 pr_err("dynamic debug error adding module: %s\n",
2370                         debug->modname);
2371 #endif
2372 }
2373 
2374 static void dynamic_debug_remove(struct _ddebug *debug)
2375 {
2376         if (debug)
2377                 ddebug_remove_module(debug->modname);
2378 }
2379 
2380 void * __weak module_alloc(unsigned long size)
2381 {
2382         return vmalloc_exec(size);
2383 }
2384 
2385 static void *module_alloc_update_bounds(unsigned long size)
2386 {
2387         void *ret = module_alloc(size);
2388 
2389         if (ret) {
2390                 mutex_lock(&module_mutex);
2391                 /* Update module bounds. */
2392                 if ((unsigned long)ret < module_addr_min)
2393                         module_addr_min = (unsigned long)ret;
2394                 if ((unsigned long)ret + size > module_addr_max)
2395                         module_addr_max = (unsigned long)ret + size;
2396                 mutex_unlock(&module_mutex);
2397         }
2398         return ret;
2399 }
2400 
2401 #ifdef CONFIG_DEBUG_KMEMLEAK
2402 static void kmemleak_load_module(const struct module *mod,
2403                                  const struct load_info *info)
2404 {
2405         unsigned int i;
2406 
2407         /* only scan the sections containing data */
2408         kmemleak_scan_area(mod, sizeof(struct module), GFP_KERNEL);
2409 
2410         for (i = 1; i < info->hdr->e_shnum; i++) {
2411                 /* Scan all writable sections that's not executable */
2412                 if (!(info->sechdrs[i].sh_flags & SHF_ALLOC) ||
2413                     !(info->sechdrs[i].sh_flags & SHF_WRITE) ||
2414                     (info->sechdrs[i].sh_flags & SHF_EXECINSTR))
2415                         continue;
2416 
2417                 kmemleak_scan_area((void *)info->sechdrs[i].sh_addr,
2418                                    info->sechdrs[i].sh_size, GFP_KERNEL);
2419         }
2420 }
2421 #else
2422 static inline void kmemleak_load_module(const struct module *mod,
2423                                         const struct load_info *info)
2424 {
2425 }
2426 #endif
2427 
2428 #ifdef CONFIG_MODULE_SIG
2429 static int module_sig_check(struct load_info *info)
2430 {
2431         int err = -ENOKEY;
2432         const unsigned long markerlen = sizeof(MODULE_SIG_STRING) - 1;
2433         const void *mod = info->hdr;
2434 
2435         if (info->len > markerlen &&
2436             memcmp(mod + info->len - markerlen, MODULE_SIG_STRING, markerlen) == 0) {
2437                 /* We truncate the module to discard the signature */
2438                 info->len -= markerlen;
2439                 err = mod_verify_sig(mod, &info->len);
2440         }
2441 
2442         if (!err) {
2443                 info->sig_ok = true;
2444                 return 0;
2445         }
2446 
2447         /* Not having a signature is only an error if we're strict. */
2448         if (err < 0 && fips_enabled)
2449                 panic("Module verification failed with error %d in FIPS mode\n",
2450                       err);
2451         if (err == -ENOKEY && !sig_enforce)
2452                 err = 0;
2453 
2454         return err;
2455 }
2456 #else /* !CONFIG_MODULE_SIG */
2457 static int module_sig_check(struct load_info *info)
2458 {
2459         return 0;
2460 }
2461 #endif /* !CONFIG_MODULE_SIG */
2462 
2463 /* Sanity checks against invalid binaries, wrong arch, weird elf version. */
2464 static int elf_header_check(struct load_info *info)
2465 {
2466         if (info->len < sizeof(*(info->hdr)))
2467                 return -ENOEXEC;
2468 
2469         if (memcmp(info->hdr->e_ident, ELFMAG, SELFMAG) != 0
2470             || info->hdr->e_type != ET_REL
2471             || !elf_check_arch(info->hdr)
2472             || info->hdr->e_shentsize != sizeof(Elf_Shdr))
2473                 return -ENOEXEC;
2474 
2475         if (info->hdr->e_shoff >= info->len
2476             || (info->hdr->e_shnum * sizeof(Elf_Shdr) >
2477                 info->len - info->hdr->e_shoff))
2478                 return -ENOEXEC;
2479 
2480         return 0;
2481 }
2482 
2483 /* Sets info->hdr and info->len. */
2484 static int copy_module_from_user(const void __user *umod, unsigned long len,
2485                                   struct load_info *info)
2486 {
2487         int err;
2488 
2489         info->len = len;
2490         if (info->len < sizeof(*(info->hdr)))
2491                 return -ENOEXEC;
2492 
2493         err = security_kernel_module_from_file(NULL);
2494         if (err)
2495                 return err;
2496 
2497         /* Suck in entire file: we'll want most of it. */
2498         info->hdr = vmalloc(info->len);
2499         if (!info->hdr)
2500                 return -ENOMEM;
2501 
2502         if (copy_from_user(info->hdr, umod, info->len) != 0) {
2503                 vfree(info->hdr);
2504                 return -EFAULT;
2505         }
2506 
2507         return 0;
2508 }
2509 
2510 /* Sets info->hdr and info->len. */
2511 static int copy_module_from_fd(int fd, struct load_info *info)
2512 {
2513         struct fd f = fdget(fd);
2514         int err;
2515         struct kstat stat;
2516         loff_t pos;
2517         ssize_t bytes = 0;
2518 
2519         if (!f.file)
2520                 return -ENOEXEC;
2521 
2522         err = security_kernel_module_from_file(f.file);
2523         if (err)
2524                 goto out;
2525 
2526         err = vfs_getattr(&f.file->f_path, &stat);
2527         if (err)
2528                 goto out;
2529 
2530         if (stat.size > INT_MAX) {
2531                 err = -EFBIG;
2532                 goto out;
2533         }
2534 
2535         /* Don't hand 0 to vmalloc, it whines. */
2536         if (stat.size == 0) {
2537                 err = -EINVAL;
2538                 goto out;
2539         }
2540 
2541         info->hdr = vmalloc(stat.size);
2542         if (!info->hdr) {
2543                 err = -ENOMEM;
2544                 goto out;
2545         }
2546 
2547         pos = 0;
2548         while (pos < stat.size) {
2549                 bytes = kernel_read(f.file, pos, (char *)(info->hdr) + pos,
2550                                     stat.size - pos);
2551                 if (bytes < 0) {
2552                         vfree(info->hdr);
2553                         err = bytes;
2554                         goto out;
2555                 }
2556                 if (bytes == 0)
2557                         break;
2558                 pos += bytes;
2559         }
2560         info->len = pos;
2561 
2562 out:
2563         fdput(f);
2564         return err;
2565 }
2566 
2567 static void free_copy(struct load_info *info)
2568 {
2569         vfree(info->hdr);
2570 }
2571 
2572 static int rewrite_section_headers(struct load_info *info, int flags)
2573 {
2574         unsigned int i;
2575 
2576         /* This should always be true, but let's be sure. */
2577         info->sechdrs[0].sh_addr = 0;
2578 
2579         for (i = 1; i < info->hdr->e_shnum; i++) {
2580                 Elf_Shdr *shdr = &info->sechdrs[i];
2581                 if (shdr->sh_type != SHT_NOBITS
2582                     && info->len < shdr->sh_offset + shdr->sh_size) {
2583                         pr_err("Module len %lu truncated\n", info->len);
2584                         return -ENOEXEC;
2585                 }
2586 
2587                 /* Mark all sections sh_addr with their address in the
2588                    temporary image. */
2589                 shdr->sh_addr = (size_t)info->hdr + shdr->sh_offset;
2590 
2591 #ifndef CONFIG_MODULE_UNLOAD
2592                 /* Don't load .exit sections */
2593                 if (strstarts(info->secstrings+shdr->sh_name, ".exit"))
2594                         shdr->sh_flags &= ~(unsigned long)SHF_ALLOC;
2595 #endif
2596         }
2597 
2598         /* Track but don't keep modinfo and version sections. */
2599         if (flags & MODULE_INIT_IGNORE_MODVERSIONS)
2600                 info->index.vers = 0; /* Pretend no __versions section! */
2601         else
2602                 info->index.vers = find_sec(info, "__versions");
2603         info->index.info = find_sec(info, ".modinfo");
2604         info->sechdrs[info->index.info].sh_flags &= ~(unsigned long)SHF_ALLOC;
2605         info->sechdrs[info->index.vers].sh_flags &= ~(unsigned long)SHF_ALLOC;
2606         return 0;
2607 }
2608 
2609 /*
2610  * Set up our basic convenience variables (pointers to section headers,
2611  * search for module section index etc), and do some basic section
2612  * verification.
2613  *
2614  * Return the temporary module pointer (we'll replace it with the final
2615  * one when we move the module sections around).
2616  */
2617 static struct module *setup_load_info(struct load_info *info, int flags)
2618 {
2619         unsigned int i;
2620         int err;
2621         struct module *mod;
2622 
2623         /* Set up the convenience variables */
2624         info->sechdrs = (void *)info->hdr + info->hdr->e_shoff;
2625         info->secstrings = (void *)info->hdr
2626                 + info->sechdrs[info->hdr->e_shstrndx].sh_offset;
2627 
2628         err = rewrite_section_headers(info, flags);
2629         if (err)
2630                 return ERR_PTR(err);
2631 
2632         /* Find internal symbols and strings. */
2633         for (i = 1; i < info->hdr->e_shnum; i++) {
2634                 if (info->sechdrs[i].sh_type == SHT_SYMTAB) {
2635                         info->index.sym = i;
2636                         info->index.str = info->sechdrs[i].sh_link;
2637                         info->strtab = (char *)info->hdr
2638                                 + info->sechdrs[info->index.str].sh_offset;
2639                         break;
2640                 }
2641         }
2642 
2643         info->index.mod = find_sec(info, ".gnu.linkonce.this_module");
2644         if (!info->index.mod) {
2645                 pr_warn("No module found in object\n");
2646                 return ERR_PTR(-ENOEXEC);
2647         }
2648         /* This is temporary: point mod into copy of data. */
2649         mod = (void *)info->sechdrs[info->index.mod].sh_addr;
2650 
2651         if (info->index.sym == 0) {
2652                 pr_warn("%s: module has no symbols (stripped?)\n", mod->name);
2653                 return ERR_PTR(-ENOEXEC);
2654         }
2655 
2656         info->index.pcpu = find_pcpusec(info);
2657 
2658         /* Check module struct version now, before we try to use module. */
2659         if (!check_modstruct_version(info->sechdrs, info->index.vers, mod))
2660                 return ERR_PTR(-ENOEXEC);
2661 
2662         return mod;
2663 }
2664 
2665 static int check_modinfo(struct module *mod, struct load_info *info, int flags)
2666 {
2667         const char *modmagic = get_modinfo(info, "vermagic");
2668         int err;
2669 
2670         if (flags & MODULE_INIT_IGNORE_VERMAGIC)
2671                 modmagic = NULL;
2672 
2673         /* This is allowed: modprobe --force will invalidate it. */
2674         if (!modmagic) {
2675                 err = try_to_force_load(mod, "bad vermagic");
2676                 if (err)
2677                         return err;
2678         } else if (!same_magic(modmagic, vermagic, info->index.vers)) {
2679                 pr_err("%s: version magic '%s' should be '%s'\n",
2680                        mod->name, modmagic, vermagic);
2681                 return -ENOEXEC;
2682         }
2683 
2684         if (!get_modinfo(info, "intree"))
2685                 add_taint_module(mod, TAINT_OOT_MODULE, LOCKDEP_STILL_OK);
2686 
2687         if (get_modinfo(info, "staging")) {
2688                 add_taint_module(mod, TAINT_CRAP, LOCKDEP_STILL_OK);
2689                 pr_warn("%s: module is from the staging directory, the quality "
2690                         "is unknown, you have been warned.\n", mod->name);
2691         }
2692 
2693         /* Set up license info based on the info section */
2694         set_license(mod, get_modinfo(info, "license"));
2695 
2696         return 0;
2697 }
2698 
2699 static int find_module_sections(struct module *mod, struct load_info *info)
2700 {
2701         mod->kp = section_objs(info, "__param",
2702                                sizeof(*mod->kp), &mod->num_kp);
2703         mod->syms = section_objs(info, "__ksymtab",
2704                                  sizeof(*mod->syms), &mod->num_syms);
2705         mod->crcs = section_addr(info, "__kcrctab");
2706         mod->gpl_syms = section_objs(info, "__ksymtab_gpl",
2707                                      sizeof(*mod->gpl_syms),
2708                                      &mod->num_gpl_syms);
2709         mod->gpl_crcs = section_addr(info, "__kcrctab_gpl");
2710         mod->gpl_future_syms = section_objs(info,
2711                                             "__ksymtab_gpl_future",
2712                                             sizeof(*mod->gpl_future_syms),
2713                                             &mod->num_gpl_future_syms);
2714         mod->gpl_future_crcs = section_addr(info, "__kcrctab_gpl_future");
2715 
2716 #ifdef CONFIG_UNUSED_SYMBOLS
2717         mod->unused_syms = section_objs(info, "__ksymtab_unused",
2718                                         sizeof(*mod->unused_syms),
2719                                         &mod->num_unused_syms);
2720         mod->unused_crcs = section_addr(info, "__kcrctab_unused");
2721         mod->unused_gpl_syms = section_objs(info, "__ksymtab_unused_gpl",
2722                                             sizeof(*mod->unused_gpl_syms),
2723                                             &mod->num_unused_gpl_syms);
2724         mod->unused_gpl_crcs = section_addr(info, "__kcrctab_unused_gpl");
2725 #endif
2726 #ifdef CONFIG_CONSTRUCTORS
2727         mod->ctors = section_objs(info, ".ctors",
2728                                   sizeof(*mod->ctors), &mod->num_ctors);
2729         if (!mod->ctors)
2730                 mod->ctors = section_objs(info, ".init_array",
2731                                 sizeof(*mod->ctors), &mod->num_ctors);
2732         else if (find_sec(info, ".init_array")) {
2733                 /*
2734                  * This shouldn't happen with same compiler and binutils
2735                  * building all parts of the module.
2736                  */
2737                 printk(KERN_WARNING "%s: has both .ctors and .init_array.\n",
2738                        mod->name);
2739                 return -EINVAL;
2740         }
2741 #endif
2742 
2743 #ifdef CONFIG_TRACEPOINTS
2744         mod->tracepoints_ptrs = section_objs(info, "__tracepoints_ptrs",
2745                                              sizeof(*mod->tracepoints_ptrs),
2746                                              &mod->num_tracepoints);
2747 #endif
2748 #ifdef HAVE_JUMP_LABEL
2749         mod->jump_entries = section_objs(info, "__jump_table",
2750                                         sizeof(*mod->jump_entries),
2751                                         &mod->num_jump_entries);
2752 #endif
2753 #ifdef CONFIG_EVENT_TRACING
2754         mod->trace_events = section_objs(info, "_ftrace_events",
2755                                          sizeof(*mod->trace_events),
2756                                          &mod->num_trace_events);
2757 #endif
2758 #ifdef CONFIG_TRACING
2759         mod->trace_bprintk_fmt_start = section_objs(info, "__trace_printk_fmt",
2760                                          sizeof(*mod->trace_bprintk_fmt_start),
2761                                          &mod->num_trace_bprintk_fmt);
2762 #endif
2763 #ifdef CONFIG_FTRACE_MCOUNT_RECORD
2764         /* sechdrs[0].sh_size is always zero */
2765         mod->ftrace_callsites = section_objs(info, "__mcount_loc",
2766                                              sizeof(*mod->ftrace_callsites),
2767                                              &mod->num_ftrace_callsites);
2768 #endif
2769 
2770         mod->extable = section_objs(info, "__ex_table",
2771                                     sizeof(*mod->extable), &mod->num_exentries);
2772 
2773         if (section_addr(info, "__obsparm"))
2774                 pr_warn("%s: Ignoring obsolete parameters\n", mod->name);
2775 
2776         info->debug = section_objs(info, "__verbose",
2777                                    sizeof(*info->debug), &info->num_debug);
2778 
2779         return 0;
2780 }
2781 
2782 static int move_module(struct module *mod, struct load_info *info)
2783 {
2784         int i;
2785         void *ptr;
2786 
2787         /* Do the allocs. */
2788         ptr = module_alloc_update_bounds(mod->core_size);
2789         /*
2790          * The pointer to this block is stored in the module structure
2791          * which is inside the block. Just mark it as not being a
2792          * leak.
2793          */
2794         kmemleak_not_leak(ptr);
2795         if (!ptr)
2796                 return -ENOMEM;
2797 
2798         memset(ptr, 0, mod->core_size);
2799         mod->module_core = ptr;
2800 
2801         if (mod->init_size) {
2802                 ptr = module_alloc_update_bounds(mod->init_size);
2803                 /*
2804                  * The pointer to this block is stored in the module structure
2805                  * which is inside the block. This block doesn't need to be
2806                  * scanned as it contains data and code that will be freed
2807                  * after the module is initialized.
2808                  */
2809                 kmemleak_ignore(ptr);
2810                 if (!ptr) {
2811                         module_free(mod, mod->module_core);
2812                         return -ENOMEM;
2813                 }
2814                 memset(ptr, 0, mod->init_size);
2815                 mod->module_init = ptr;
2816         } else
2817                 mod->module_init = NULL;
2818 
2819         /* Transfer each section which specifies SHF_ALLOC */
2820         pr_debug("final section addresses:\n");
2821         for (i = 0; i < info->hdr->e_shnum; i++) {
2822                 void *dest;
2823                 Elf_Shdr *shdr = &info->sechdrs[i];
2824 
2825                 if (!(shdr->sh_flags & SHF_ALLOC))
2826                         continue;
2827 
2828                 if (shdr->sh_entsize & INIT_OFFSET_MASK)
2829                         dest = mod->module_init
2830                                 + (shdr->sh_entsize & ~INIT_OFFSET_MASK);
2831                 else
2832                         dest = mod->module_core + shdr->sh_entsize;
2833 
2834                 if (shdr->sh_type != SHT_NOBITS)
2835                         memcpy(dest, (void *)shdr->sh_addr, shdr->sh_size);
2836                 /* Update sh_addr to point to copy in image. */
2837                 shdr->sh_addr = (unsigned long)dest;
2838                 pr_debug("\t0x%lx %s\n",
2839                          (long)shdr->sh_addr, info->secstrings + shdr->sh_name);
2840         }
2841 
2842         return 0;
2843 }
2844 
2845 static int check_module_license_and_versions(struct module *mod)
2846 {
2847         /*
2848          * ndiswrapper is under GPL by itself, but loads proprietary modules.
2849          * Don't use add_taint_module(), as it would prevent ndiswrapper from
2850          * using GPL-only symbols it needs.
2851          */
2852         if (strcmp(mod->name, "ndiswrapper") == 0)
2853                 add_taint(TAINT_PROPRIETARY_MODULE, LOCKDEP_NOW_UNRELIABLE);
2854 
2855         /* driverloader was caught wrongly pretending to be under GPL */
2856         if (strcmp(mod->name, "driverloader") == 0)
2857                 add_taint_module(mod, TAINT_PROPRIETARY_MODULE,
2858                                  LOCKDEP_NOW_UNRELIABLE);
2859 
2860         /* lve claims to be GPL but upstream won't provide source */
2861         if (strcmp(mod->name, "lve") == 0)
2862                 add_taint_module(mod, TAINT_PROPRIETARY_MODULE,
2863                                  LOCKDEP_NOW_UNRELIABLE);
2864 
2865 #ifdef CONFIG_MODVERSIONS
2866         if ((mod->num_syms && !mod->crcs)
2867             || (mod->num_gpl_syms && !mod->gpl_crcs)
2868             || (mod->num_gpl_future_syms && !mod->gpl_future_crcs)
2869 #ifdef CONFIG_UNUSED_SYMBOLS
2870             || (mod->num_unused_syms && !mod->unused_crcs)
2871             || (mod->num_unused_gpl_syms && !mod->unused_gpl_crcs)
2872 #endif
2873                 ) {
2874                 return try_to_force_load(mod,
2875                                          "no versions for exported symbols");
2876         }
2877 #endif
2878         return 0;
2879 }
2880 
2881 static void flush_module_icache(const struct module *mod)
2882 {
2883         mm_segment_t old_fs;
2884 
2885         /* flush the icache in correct context */
2886         old_fs = get_fs();
2887         set_fs(KERNEL_DS);
2888 
2889         /*
2890          * Flush the instruction cache, since we've played with text.
2891          * Do it before processing of module parameters, so the module
2892          * can provide parameter accessor functions of its own.
2893          */
2894         if (mod->module_init)
2895                 flush_icache_range((unsigned long)mod->module_init,
2896                                    (unsigned long)mod->module_init
2897                                    + mod->init_size);
2898         flush_icache_range((unsigned long)mod->module_core,
2899                            (unsigned long)mod->module_core + mod->core_size);
2900 
2901         set_fs(old_fs);
2902 }
2903 
2904 int __weak module_frob_arch_sections(Elf_Ehdr *hdr,
2905                                      Elf_Shdr *sechdrs,
2906                                      char *secstrings,
2907                                      struct module *mod)
2908 {
2909         return 0;
2910 }
2911 
2912 static struct module *layout_and_allocate(struct load_info *info, int flags)
2913 {
2914         /* Module within temporary copy. */
2915         struct module *mod;
2916         int err;
2917 
2918         mod = setup_load_info(info, flags);
2919         if (IS_ERR(mod))
2920                 return mod;
2921 
2922         err = check_modinfo(mod, info, flags);
2923         if (err)
2924                 return ERR_PTR(err);
2925 
2926         /* Allow arches to frob section contents and sizes.  */
2927         err = module_frob_arch_sections(info->hdr, info->sechdrs,
2928                                         info->secstrings, mod);
2929         if (err < 0)
2930                 return ERR_PTR(err);
2931 
2932         /* We will do a special allocation for per-cpu sections later. */
2933         info->sechdrs[info->index.pcpu].sh_flags &= ~(unsigned long)SHF_ALLOC;
2934 
2935         /* Determine total sizes, and put offsets in sh_entsize.  For now
2936            this is done generically; there doesn't appear to be any
2937            special cases for the architectures. */
2938         layout_sections(mod, info);
2939         layout_symtab(mod, info);
2940 
2941         /* Allocate and move to the final place */
2942         err = move_module(mod, info);
2943         if (err)
2944                 return ERR_PTR(err);
2945 
2946         /* Module has been copied to its final place now: return it. */
2947         mod = (void *)info->sechdrs[info->index.mod].sh_addr;
2948         kmemleak_load_module(mod, info);
2949         return mod;
2950 }
2951 
2952 /* mod is no longer valid after this! */
2953 static void module_deallocate(struct module *mod, struct load_info *info)
2954 {
2955         percpu_modfree(mod);
2956         module_free(mod, mod->module_init);
2957         module_free(mod, mod->module_core);
2958 }
2959 
2960 int __weak module_finalize(const Elf_Ehdr *hdr,
2961                            const Elf_Shdr *sechdrs,
2962                            struct module *me)
2963 {
2964         return 0;
2965 }
2966 
2967 static int post_relocation(struct module *mod, const struct load_info *info)
2968 {
2969         /* Sort exception table now relocations are done. */
2970         sort_extable(mod->extable, mod->extable + mod->num_exentries);
2971 
2972         /* Copy relocated percpu area over. */
2973         percpu_modcopy(mod, (void *)info->sechdrs[info->index.pcpu].sh_addr,
2974                        info->sechdrs[info->index.pcpu].sh_size);
2975 
2976         /* Setup kallsyms-specific fields. */
2977         add_kallsyms(mod, info);
2978 
2979         /* Arch-specific module finalizing. */
2980         return module_finalize(info->hdr, info->sechdrs, mod);
2981 }
2982 
2983 /* Is this module of this name done loading?  No locks held. */
2984 static bool finished_loading(const char *name)
2985 {
2986         struct module *mod;
2987         bool ret;
2988 
2989         mutex_lock(&module_mutex);
2990         mod = find_module_all(name, strlen(name), true);
2991         ret = !mod || mod->state == MODULE_STATE_LIVE
2992                 || mod->state == MODULE_STATE_GOING;
2993         mutex_unlock(&module_mutex);
2994 
2995         return ret;
2996 }
2997 
2998 /* Call module constructors. */
2999 static void do_mod_ctors(struct module *mod)
3000 {
3001 #ifdef CONFIG_CONSTRUCTORS
3002         unsigned long i;
3003 
3004         for (i = 0; i < mod->num_ctors; i++)
3005                 mod->ctors[i]();
3006 #endif
3007 }
3008 
3009 /* This is where the real work happens */
3010 static int do_init_module(struct module *mod)
3011 {
3012         int ret = 0;
3013 
3014         /*
3015          * We want to find out whether @mod uses async during init.  Clear
3016          * PF_USED_ASYNC.  async_schedule*() will set it.
3017          */
3018         current->flags &= ~PF_USED_ASYNC;
3019 
3020         blocking_notifier_call_chain(&module_notify_list,
3021                         MODULE_STATE_COMING, mod);
3022 
3023         /* Set RO and NX regions for core */
3024         set_section_ro_nx(mod->module_core,
3025                                 mod->core_text_size,
3026                                 mod->core_ro_size,
3027                                 mod->core_size);
3028 
3029         /* Set RO and NX regions for init */
3030         set_section_ro_nx(mod->module_init,
3031                                 mod->init_text_size,
3032                                 mod->init_ro_size,
3033                                 mod->init_size);
3034 
3035         do_mod_ctors(mod);
3036         /* Start the module */
3037         if (mod->init != NULL)
3038                 ret = do_one_initcall(mod->init);
3039         if (ret < 0) {
3040                 /* Init routine failed: abort.  Try to protect us from
3041                    buggy refcounters. */
3042                 mod->state = MODULE_STATE_GOING;
3043                 synchronize_sched();
3044                 module_put(mod);
3045                 blocking_notifier_call_chain(&module_notify_list,
3046                                              MODULE_STATE_GOING, mod);
3047                 free_module(mod);
3048                 wake_up_all(&module_wq);
3049                 return ret;
3050         }
3051         if (ret > 0) {
3052                 pr_warn("%s: '%s'->init suspiciously returned %d, it should "
3053                         "follow 0/-E convention\n"
3054                         "%s: loading module anyway...\n",
3055                         __func__, mod->name, ret, __func__);
3056                 dump_stack();
3057         }
3058 
3059         /* Now it's a first class citizen! */
3060         mod->state = MODULE_STATE_LIVE;
3061         blocking_notifier_call_chain(&module_notify_list,
3062                                      MODULE_STATE_LIVE, mod);
3063 
3064         /*
3065          * We need to finish all async code before the module init sequence
3066          * is done.  This has potential to deadlock.  For example, a newly
3067          * detected block device can trigger request_module() of the
3068          * default iosched from async probing task.  Once userland helper
3069          * reaches here, async_synchronize_full() will wait on the async
3070          * task waiting on request_module() and deadlock.
3071          *
3072          * This deadlock is avoided by perfomring async_synchronize_full()
3073          * iff module init queued any async jobs.  This isn't a full
3074          * solution as it will deadlock the same if module loading from
3075          * async jobs nests more than once; however, due to the various
3076          * constraints, this hack seems to be the best option for now.
3077          * Please refer to the following thread for details.
3078          *
3079          * http://thread.gmane.org/gmane.linux.kernel/1420814
3080          */
3081         if (current->flags & PF_USED_ASYNC)
3082                 async_synchronize_full();
3083 
3084         mutex_lock(&module_mutex);
3085         /* Drop initial reference. */
3086         module_put(mod);
3087         trim_init_extable(mod);
3088 #ifdef CONFIG_KALLSYMS
3089         mod->num_symtab = mod->core_num_syms;
3090         mod->symtab = mod->core_symtab;
3091         mod->strtab = mod->core_strtab;
3092 #endif
3093         unset_module_init_ro_nx(mod);
3094         module_free(mod, mod->module_init);
3095         mod->module_init = NULL;
3096         mod->init_size = 0;
3097         mod->init_ro_size = 0;
3098         mod->init_text_size = 0;
3099         mutex_unlock(&module_mutex);
3100         wake_up_all(&module_wq);
3101 
3102         return 0;
3103 }
3104 
3105 static int may_init_module(void)
3106 {
3107         if (!capable(CAP_SYS_MODULE) || modules_disabled)
3108                 return -EPERM;
3109 
3110         return 0;
3111 }
3112 
3113 /*
3114  * We try to place it in the list now to make sure it's unique before
3115  * we dedicate too many resources.  In particular, temporary percpu
3116  * memory exhaustion.
3117  */
3118 static int add_unformed_module(struct module *mod)
3119 {
3120         int err;
3121         struct module *old;
3122 
3123         mod->state = MODULE_STATE_UNFORMED;
3124 
3125 again:
3126         mutex_lock(&module_mutex);
3127         old = find_module_all(mod->name, strlen(mod->name), true);
3128         if (old != NULL) {
3129                 if (old->state == MODULE_STATE_COMING
3130                     || old->state == MODULE_STATE_UNFORMED) {
3131                         /* Wait in case it fails to load. */
3132                         mutex_unlock(&module_mutex);
3133                         err = wait_event_interruptible(module_wq,
3134                                                finished_loading(mod->name));
3135                         if (err)
3136                                 goto out_unlocked;
3137                         goto again;
3138                 }
3139                 err = -EEXIST;
3140                 goto out;
3141         }
3142         list_add_rcu(&mod->list, &modules);
3143         err = 0;
3144 
3145 out:
3146         mutex_unlock(&module_mutex);
3147 out_unlocked:
3148         return err;
3149 }
3150 
3151 static int complete_formation(struct module *mod, struct load_info *info)
3152 {
3153         int err;
3154 
3155         mutex_lock(&module_mutex);
3156 
3157         /* Find duplicate symbols (must be called under lock). */
3158         err = verify_export_symbols(mod);
3159         if (err < 0)
3160                 goto out;
3161 
3162         /* This relies on module_mutex for list integrity. */
3163         module_bug_finalize(info->hdr, info->sechdrs, mod);
3164 
3165         /* Mark state as coming so strong_try_module_get() ignores us,
3166          * but kallsyms etc. can see us. */
3167         mod->state = MODULE_STATE_COMING;
3168 
3169 out:
3170         mutex_unlock(&module_mutex);
3171         return err;
3172 }
3173 
3174 static int unknown_module_param_cb(char *param, char *val, const char *modname)
3175 {
3176         /* Check for magic 'dyndbg' arg */ 
3177         int ret = ddebug_dyndbg_module_param_cb(param, val, modname);
3178         if (ret != 0)
3179                 pr_warn("%s: unknown parameter '%s' ignored\n", modname, param);
3180         return 0;
3181 }
3182 
3183 /* Allocate and load the module: note that size of section 0 is always
3184    zero, and we rely on this for optional sections. */
3185 static int load_module(struct load_info *info, const char __user *uargs,
3186                        int flags)
3187 {
3188         struct module *mod;
3189         long err;
3190 
3191         err = module_sig_check(info);
3192         if (err)
3193                 goto free_copy;
3194 
3195         err = elf_header_check(info);
3196         if (err)
3197                 goto free_copy;
3198 
3199         /* Figure out module layout, and allocate all the memory. */
3200         mod = layout_and_allocate(info, flags);
3201         if (IS_ERR(mod)) {
3202                 err = PTR_ERR(mod);
3203                 goto free_copy;
3204         }
3205 
3206         /* Reserve our place in the list. */
3207         err = add_unformed_module(mod);
3208         if (err)
3209                 goto free_module;
3210 
3211 #ifdef CONFIG_MODULE_SIG
3212         mod->sig_ok = info->sig_ok;
3213         if (!mod->sig_ok) {
3214                 pr_notice_once("%s: module verification failed: signature "
3215                                "and/or  required key missing - tainting "
3216                                "kernel\n", mod->name);
3217                 add_taint_module(mod, TAINT_FORCED_MODULE, LOCKDEP_STILL_OK);
3218         }
3219 #endif
3220 
3221         /* To avoid stressing percpu allocator, do this once we're unique. */
3222         err = percpu_modalloc(mod, info);
3223         if (err)
3224                 goto unlink_mod;
3225 
3226         /* Now module is in final location, initialize linked lists, etc. */
3227         err = module_unload_init(mod);
3228         if (err)
3229                 goto unlink_mod;
3230 
3231         /* Now we've got everything in the final locations, we can
3232          * find optional sections. */
3233         err = find_module_sections(mod, info);
3234         if (err)
3235                 goto free_unload;
3236 
3237         err = check_module_license_and_versions(mod);
3238         if (err)
3239                 goto free_unload;
3240 
3241         /* Set up MODINFO_ATTR fields */
3242         setup_modinfo(mod, info);
3243 
3244         /* Fix up syms, so that st_value is a pointer to location. */
3245         err = simplify_symbols(mod, info);
3246         if (err < 0)
3247                 goto free_modinfo;
3248 
3249         err = apply_relocations(mod, info);
3250         if (err < 0)
3251                 goto free_modinfo;
3252 
3253         err = post_relocation(mod, info);
3254         if (err < 0)
3255                 goto free_modinfo;
3256 
3257         flush_module_icache(mod);
3258 
3259         /* Now copy in args */
3260         mod->args = strndup_user(uargs, ~0UL >> 1);
3261         if (IS_ERR(mod->args)) {
3262                 err = PTR_ERR(mod->args);
3263                 goto free_arch_cleanup;
3264         }
3265 
3266         dynamic_debug_setup(info->debug, info->num_debug);
3267 
3268         /* Finally it's fully formed, ready to start executing. */
3269         err = complete_formation(mod, info);
3270         if (err)
3271                 goto ddebug_cleanup;
3272 
3273         /* Module is ready to execute: parsing args may do that. */
3274         err = parse_args(mod->name, mod->args, mod->kp, mod->num_kp,
3275                          -32768, 32767, unknown_module_param_cb);
3276         if (err < 0)
3277                 goto bug_cleanup;
3278 
3279         /* Link in to syfs. */
3280         err = mod_sysfs_setup(mod, info, mod->kp, mod->num_kp);
3281         if (err < 0)
3282                 goto bug_cleanup;
3283 
3284         /* Get rid of temporary copy. */
3285         free_copy(info);
3286 
3287         /* Done! */
3288         trace_module_load(mod);
3289 
3290         return do_init_module(mod);
3291 
3292  bug_cleanup:
3293         /* module_bug_cleanup needs module_mutex protection */
3294         mutex_lock(&module_mutex);
3295         module_bug_cleanup(mod);
3296         mutex_unlock(&module_mutex);
3297  ddebug_cleanup:
3298         dynamic_debug_remove(info->debug);
3299         synchronize_sched();
3300         kfree(mod->args);
3301  free_arch_cleanup:
3302         module_arch_cleanup(mod);
3303  free_modinfo:
3304         free_modinfo(mod);
3305  free_unload:
3306         module_unload_free(mod);
3307  unlink_mod:
3308         mutex_lock(&module_mutex);
3309         /* Unlink carefully: kallsyms could be walking list. */
3310         list_del_rcu(&mod->list);
3311         wake_up_all(&module_wq);
3312         mutex_unlock(&module_mutex);
3313  free_module:
3314         module_deallocate(mod, info);
3315  free_copy:
3316         free_copy(info);
3317         return err;
3318 }
3319 
3320 SYSCALL_DEFINE3(init_module, void __user *, umod,
3321                 unsigned long, len, const char __user *, uargs)
3322 {
3323         int err;
3324         struct load_info info = { };
3325 
3326         err = may_init_module();
3327         if (err)
3328                 return err;
3329 
3330         pr_debug("init_module: umod=%p, len=%lu, uargs=%p\n",
3331                umod, len, uargs);
3332 
3333         err = copy_module_from_user(umod, len, &info);
3334         if (err)
3335                 return err;
3336 
3337         return load_module(&info, uargs, 0);
3338 }
3339 
3340 SYSCALL_DEFINE3(finit_module, int, fd, const char __user *, uargs, int, flags)
3341 {
3342         int err;
3343         struct load_info info = { };
3344 
3345         err = may_init_module();
3346         if (err)
3347                 return err;
3348 
3349         pr_debug("finit_module: fd=%d, uargs=%p, flags=%i\n", fd, uargs, flags);
3350 
3351         if (flags & ~(MODULE_INIT_IGNORE_MODVERSIONS
3352                       |MODULE_INIT_IGNORE_VERMAGIC))
3353                 return -EINVAL;
3354 
3355         err = copy_module_from_fd(fd, &info);
3356         if (err)
3357                 return err;
3358 
3359         return load_module(&info, uargs, flags);
3360 }
3361 
3362 static inline int within(unsigned long addr, void *start, unsigned long size)
3363 {
3364         return ((void *)addr >= start && (void *)addr < start + size);
3365 }
3366 
3367 #ifdef CONFIG_KALLSYMS
3368 /*
3369  * This ignores the intensely annoying "mapping symbols" found
3370  * in ARM ELF files: $a, $t and $d.
3371  */
3372 static inline int is_arm_mapping_symbol(const char *str)
3373 {
3374         return str[0] == '$' && strchr("atd", str[1])
3375                && (str[2] == '\0' || str[2] == '.');
3376 }
3377 
3378 static const char *get_ksymbol(struct module *mod,
3379                                unsigned long addr,
3380                                unsigned long *size,
3381                                unsigned long *offset)
3382 {
3383         unsigned int i, best = 0;
3384         unsigned long nextval;
3385 
3386         /* At worse, next value is at end of module */
3387         if (within_module_init(addr, mod))
3388                 nextval = (unsigned long)mod->module_init+mod->init_text_size;
3389         else
3390                 nextval = (unsigned long)mod->module_core+mod->core_text_size;
3391 
3392         /* Scan for closest preceding symbol, and next symbol. (ELF
3393            starts real symbols at 1). */
3394         for (i = 1; i < mod->num_symtab; i++) {
3395                 if (mod->symtab[i].st_shndx == SHN_UNDEF)
3396                         continue;
3397 
3398                 /* We ignore unnamed symbols: they're uninformative
3399                  * and inserted at a whim. */
3400                 if (mod->symtab[i].st_value <= addr
3401                     && mod->symtab[i].st_value > mod->symtab[best].st_value
3402                     && *(mod->strtab + mod->symtab[i].st_name) != '\0'
3403                     && !is_arm_mapping_symbol(mod->strtab + mod->symtab[i].st_name))
3404                         best = i;
3405                 if (mod->symtab[i].st_value > addr
3406                     && mod->symtab[i].st_value < nextval
3407                     && *(mod->strtab + mod->symtab[i].st_name) != '\0'
3408                     && !is_arm_mapping_symbol(mod->strtab + mod->symtab[i].st_name))
3409                         nextval = mod->symtab[i].st_value;
3410         }
3411 
3412         if (!best)
3413                 return NULL;
3414 
3415         if (size)
3416                 *size = nextval - mod->symtab[best].st_value;
3417         if (offset)
3418                 *offset = addr - mod->symtab[best].st_value;
3419         return mod->strtab + mod->symtab[best].st_name;
3420 }
3421 
3422 /* For kallsyms to ask for address resolution.  NULL means not found.  Careful
3423  * not to lock to avoid deadlock on oopses, simply disable preemption. */
3424 const char *module_address_lookup(unsigned long addr,
3425                             unsigned long *size,
3426                             unsigned long *offset,
3427                             char **modname,
3428                             char *namebuf)
3429 {
3430         struct module *mod;
3431         const char *ret = NULL;
3432 
3433         preempt_disable();
3434         list_for_each_entry_rcu(mod, &modules, list) {
3435                 if (mod->state == MODULE_STATE_UNFORMED)
3436                         continue;
3437                 if (within_module_init(addr, mod) ||
3438                     within_module_core(addr, mod)) {
3439                         if (modname)
3440                                 *modname = mod->name;
3441                         ret = get_ksymbol(mod, addr, size, offset);
3442                         break;
3443                 }
3444         }
3445         /* Make a copy in here where it's safe */
3446         if (ret) {
3447                 strncpy(namebuf, ret, KSYM_NAME_LEN - 1);
3448                 ret = namebuf;
3449         }
3450         preempt_enable();
3451         return ret;
3452 }
3453 
3454 int lookup_module_symbol_name(unsigned long addr, char *symname)
3455 {
3456         struct module *mod;
3457 
3458         preempt_disable();
3459         list_for_each_entry_rcu(mod, &modules, list) {
3460                 if (mod->state == MODULE_STATE_UNFORMED)
3461                         continue;
3462                 if (within_module_init(addr, mod) ||
3463                     within_module_core(addr, mod)) {
3464                         const char *sym;
3465 
3466                         sym = get_ksymbol(mod, addr, NULL, NULL);
3467                         if (!sym)
3468                                 goto out;
3469                         strlcpy(symname, sym, KSYM_NAME_LEN);
3470                         preempt_enable();
3471                         return 0;
3472                 }
3473         }
3474 out:
3475         preempt_enable();
3476         return -ERANGE;
3477 }
3478 
3479 int lookup_module_symbol_attrs(unsigned long addr, unsigned long *size,
3480                         unsigned long *offset, char *modname, char *name)
3481 {
3482         struct module *mod;
3483 
3484         preempt_disable();
3485         list_for_each_entry_rcu(mod, &modules, list) {
3486                 if (mod->state == MODULE_STATE_UNFORMED)
3487                         continue;
3488                 if (within_module_init(addr, mod) ||
3489                     within_module_core(addr, mod)) {
3490                         const char *sym;
3491 
3492                         sym = get_ksymbol(mod, addr, size, offset);
3493                         if (!sym)
3494                                 goto out;
3495                         if (modname)
3496                                 strlcpy(modname, mod->name, MODULE_NAME_LEN);
3497                         if (name)
3498                                 strlcpy(name, sym, KSYM_NAME_LEN);
3499                         preempt_enable();
3500                         return 0;
3501                 }
3502         }
3503 out:
3504         preempt_enable();
3505         return -ERANGE;
3506 }
3507 
3508 int module_get_kallsym(unsigned int symnum, unsigned long *value, char *type,
3509                         char *name, char *module_name, int *exported)
3510 {
3511         struct module *mod;
3512 
3513         preempt_disable();
3514         list_for_each_entry_rcu(mod, &modules, list) {
3515                 if (mod->state == MODULE_STATE_UNFORMED)
3516                         continue;
3517                 if (symnum < mod->num_symtab) {
3518                         *value = mod->symtab[symnum].st_value;
3519                         *type = mod->symtab[symnum].st_info;
3520                         strlcpy(name, mod->strtab + mod->symtab[symnum].st_name,
3521                                 KSYM_NAME_LEN);
3522                         strlcpy(module_name, mod->name, MODULE_NAME_LEN);
3523                         *exported = is_exported(name, *value, mod);
3524                         preempt_enable();
3525                         return 0;
3526                 }
3527                 symnum -= mod->num_symtab;
3528         }
3529         preempt_enable();
3530         return -ERANGE;
3531 }
3532 
3533 static unsigned long mod_find_symname(struct module *mod, const char *name)
3534 {
3535         unsigned int i;
3536 
3537         for (i = 0; i < mod->num_symtab; i++)
3538                 if (strcmp(name, mod->strtab+mod->symtab[i].st_name) == 0 &&
3539                     mod->symtab[i].st_info != 'U')
3540                         return mod->symtab[i].st_value;
3541         return 0;
3542 }
3543 
3544 /* Look for this name: can be of form module:name. */
3545 unsigned long module_kallsyms_lookup_name(const char *name)
3546 {
3547         struct module *mod;
3548         char *colon;
3549         unsigned long ret = 0;
3550 
3551         /* Don't lock: we're in enough trouble already. */
3552         preempt_disable();
3553         if ((colon = strchr(name, ':')) != NULL) {
3554                 if ((mod = find_module_all(name, colon - name, false)) != NULL)
3555                         ret = mod_find_symname(mod, colon+1);
3556         } else {
3557                 list_for_each_entry_rcu(mod, &modules, list) {
3558                         if (mod->state == MODULE_STATE_UNFORMED)
3559                                 continue;
3560                         if ((ret = mod_find_symname(mod, name)) != 0)
3561                                 break;
3562                 }
3563         }
3564         preempt_enable();
3565         return ret;
3566 }
3567 
3568 int module_kallsyms_on_each_symbol(int (*fn)(void *, const char *,
3569                                              struct module *, unsigned long),
3570                                    void *data)
3571 {
3572         struct module *mod;
3573         unsigned int i;
3574         int ret;
3575 
3576         list_for_each_entry(mod, &modules, list) {
3577                 if (mod->state == MODULE_STATE_UNFORMED)
3578                         continue;
3579                 for (i = 0; i < mod->num_symtab; i++) {
3580                         ret = fn(data, mod->strtab + mod->symtab[i].st_name,
3581                                  mod, mod->symtab[i].st_value);
3582                         if (ret != 0)
3583                                 return ret;
3584                 }
3585         }
3586         return 0;
3587 }
3588 #endif /* CONFIG_KALLSYMS */
3589 
3590 static char *module_flags(struct module *mod, char *buf)
3591 {
3592         int bx = 0;
3593 
3594         BUG_ON(mod->state == MODULE_STATE_UNFORMED);
3595         if (mod->taints ||
3596             mod->state == MODULE_STATE_GOING ||
3597             mod->state == MODULE_STATE_COMING) {
3598                 buf[bx++] = '(';
3599                 bx += module_flags_taint(mod, buf + bx);
3600                 /* Show a - for module-is-being-unloaded */
3601                 if (mod->state == MODULE_STATE_GOING)
3602                         buf[bx++] = '-';
3603                 /* Show a + for module-is-being-loaded */
3604                 if (mod->state == MODULE_STATE_COMING)
3605                         buf[bx++] = '+';
3606                 buf[bx++] = ')';
3607         }
3608         buf[bx] = '\0';
3609 
3610         return buf;
3611 }
3612 
3613 #ifdef CONFIG_PROC_FS
3614 /* Called by the /proc file system to return a list of modules. */
3615 static void *m_start(struct seq_file *m, loff_t *pos)
3616 {
3617         mutex_lock(&module_mutex);
3618         return seq_list_start(&modules, *pos);
3619 }
3620 
3621 static void *m_next(struct seq_file *m, void *p, loff_t *pos)
3622 {
3623         return seq_list_next(p, &modules, pos);
3624 }
3625 
3626 static void m_stop(struct seq_file *m, void *p)
3627 {
3628         mutex_unlock(&module_mutex);
3629 }
3630 
3631 static int m_show(struct seq_file *m, void *p)
3632 {
3633         struct module *mod = list_entry(p, struct module, list);
3634         char buf[8];
3635 
3636         /* We always ignore unformed modules. */
3637         if (mod->state == MODULE_STATE_UNFORMED)
3638                 return 0;
3639 
3640         seq_printf(m, "%s %u",
3641                    mod->name, mod->init_size + mod->core_size);
3642         print_unload_info(m, mod);
3643 
3644         /* Informative for users. */
3645         seq_printf(m, " %s",
3646                    mod->state == MODULE_STATE_GOING ? "Unloading":
3647                    mod->state == MODULE_STATE_COMING ? "Loading":
3648                    "Live");
3649         /* Used by oprofile and other similar tools. */
3650         seq_printf(m, " 0x%pK", mod->module_core);
3651 
3652         /* Taints info */
3653         if (mod->taints)
3654                 seq_printf(m, " %s", module_flags(mod, buf));
3655 
3656         seq_printf(m, "\n");
3657         return 0;
3658 }
3659 
3660 /* Format: modulename size refcount deps address
3661 
3662    Where refcount is a number or -, and deps is a comma-separated list
3663    of depends or -.
3664 */
3665 static const struct seq_operations modules_op = {
3666         .start  = m_start,
3667         .next   = m_next,
3668         .stop   = m_stop,
3669         .show   = m_show
3670 };
3671 
3672 static int modules_open(struct inode *inode, struct file *file)
3673 {
3674         return seq_open(file, &modules_op);
3675 }
3676 
3677 static const struct file_operations proc_modules_operations = {
3678         .open           = modules_open,
3679         .read           = seq_read,
3680         .llseek         = seq_lseek,
3681         .release        = seq_release,
3682 };
3683 
3684 static int __init proc_modules_init(void)
3685 {
3686         proc_create("modules", 0, NULL, &proc_modules_operations);
3687         return 0;
3688 }
3689 module_init(proc_modules_init);
3690 #endif
3691 
3692 /* Given an address, look for it in the module exception tables. */
3693 const struct exception_table_entry *search_module_extables(unsigned long addr)
3694 {
3695         const struct exception_table_entry *e = NULL;
3696         struct module *mod;
3697 
3698         preempt_disable();
3699         list_for_each_entry_rcu(mod, &modules, list) {
3700                 if (mod->state == MODULE_STATE_UNFORMED)
3701                         continue;
3702                 if (mod->num_exentries == 0)
3703                         continue;
3704 
3705                 e = search_extable(mod->extable,
3706                                    mod->extable + mod->num_exentries - 1,
3707                                    addr);
3708                 if (e)
3709                         break;
3710         }
3711         preempt_enable();
3712 
3713         /* Now, if we found one, we are running inside it now, hence
3714            we cannot unload the module, hence no refcnt needed. */
3715         return e;
3716 }
3717 
3718 /*
3719  * is_module_address - is this address inside a module?
3720  * @addr: the address to check.
3721  *
3722  * See is_module_text_address() if you simply want to see if the address
3723  * is code (not data).
3724  */
3725 bool is_module_address(unsigned long addr)
3726 {
3727         bool ret;
3728 
3729         preempt_disable();
3730         ret = __module_address(addr) != NULL;
3731         preempt_enable();
3732 
3733         return ret;
3734 }
3735 
3736 /*
3737  * __module_address - get the module which contains an address.
3738  * @addr: the address.
3739  *
3740  * Must be called with preempt disabled or module mutex held so that
3741  * module doesn't get freed during this.
3742  */
3743 struct module *__module_address(unsigned long addr)
3744 {
3745         struct module *mod;
3746 
3747         if (addr < module_addr_min || addr > module_addr_max)
3748                 return NULL;
3749 
3750         list_for_each_entry_rcu(mod, &modules, list) {
3751                 if (mod->state == MODULE_STATE_UNFORMED)
3752                         continue;
3753                 if (within_module_core(addr, mod)
3754                     || within_module_init(addr, mod))
3755                         return mod;
3756         }
3757         return NULL;
3758 }
3759 EXPORT_SYMBOL_GPL(__module_address);
3760 
3761 /*
3762  * is_module_text_address - is this address inside module code?
3763  * @addr: the address to check.
3764  *
3765  * See is_module_address() if you simply want to see if the address is
3766  * anywhere in a module.  See kernel_text_address() for testing if an
3767  * address corresponds to kernel or module code.
3768  */
3769 bool is_module_text_address(unsigned long addr)
3770 {
3771         bool ret;
3772 
3773         preempt_disable();
3774         ret = __module_text_address(addr) != NULL;
3775         preempt_enable();
3776 
3777         return ret;
3778 }
3779 
3780 /*
3781  * __module_text_address - get the module whose code contains an address.
3782  * @addr: the address.
3783  *
3784  * Must be called with preempt disabled or module mutex held so that
3785  * module doesn't get freed during this.
3786  */
3787 struct module *__module_text_address(unsigned long addr)
3788 {
3789         struct module *mod = __module_address(addr);
3790         if (mod) {
3791                 /* Make sure it's within the text section. */
3792                 if (!within(addr, mod->module_init, mod->init_text_size)
3793                     && !within(addr, mod->module_core, mod->core_text_size))
3794                         mod = NULL;
3795         }
3796         return mod;
3797 }
3798 EXPORT_SYMBOL_GPL(__module_text_address);
3799 
3800 /* Don't grab lock, we're oopsing. */
3801 void print_modules(void)
3802 {
3803         struct module *mod;
3804         char buf[8];
3805 
3806         printk(KERN_DEFAULT "Modules linked in:");
3807         /* Most callers should already have preempt disabled, but make sure */
3808         preempt_disable();
3809         list_for_each_entry_rcu(mod, &modules, list) {
3810                 if (mod->state == MODULE_STATE_UNFORMED)
3811                         continue;
3812                 printk(" %s%s", mod->name, module_flags(mod, buf));
3813         }
3814         preempt_enable();
3815         if (last_unloaded_module[0])
3816                 printk(" [last unloaded: %s]", last_unloaded_module);
3817         printk("\n");
3818 }
3819 
3820 #ifdef CONFIG_MODVERSIONS
3821 /* Generate the signature for all relevant module structures here.
3822  * If these change, we don't want to try to parse the module. */
3823 void module_layout(struct module *mod,
3824                    struct modversion_info *ver,
3825                    struct kernel_param *kp,
3826                    struct kernel_symbol *ks,
3827                    struct tracepoint * const *tp)
3828 {
3829 }
3830 EXPORT_SYMBOL(module_layout);
3831 #endif
3832 

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