Version:  2.0.40 2.2.26 2.4.37 3.5 3.6 3.7 3.8 3.9 3.10 3.11 3.12 3.13 3.14 3.15 3.16 3.17 3.18 3.19 4.0 4.1

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

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