Version:  2.0.40 2.2.26 2.4.37 3.3 3.4 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

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 evalute if this is the right api to use and if "
391                         "it really is, submit a report the linux kernel "
392                         "mailinglist 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         mutex_lock(&module_mutex);
1229         sym = find_symbol(name, &owner, &crc,
1230                           !(mod->taints & (1 << TAINT_PROPRIETARY_MODULE)), true);
1231         if (!sym)
1232                 goto unlock;
1233 
1234         if (!check_version(info->sechdrs, info->index.vers, name, mod, crc,
1235                            owner)) {
1236                 sym = ERR_PTR(-EINVAL);
1237                 goto getname;
1238         }
1239 
1240         err = ref_module(mod, owner);
1241         if (err) {
1242                 sym = ERR_PTR(err);
1243                 goto getname;
1244         }
1245 
1246 getname:
1247         /* We must make copy under the lock if we failed to get ref. */
1248         strncpy(ownername, module_name(owner), MODULE_NAME_LEN);
1249 unlock:
1250         mutex_unlock(&module_mutex);
1251         return sym;
1252 }
1253 
1254 static const struct kernel_symbol *
1255 resolve_symbol_wait(struct module *mod,
1256                     const struct load_info *info,
1257                     const char *name)
1258 {
1259         const struct kernel_symbol *ksym;
1260         char owner[MODULE_NAME_LEN];
1261 
1262         if (wait_event_interruptible_timeout(module_wq,
1263                         !IS_ERR(ksym = resolve_symbol(mod, info, name, owner))
1264                         || PTR_ERR(ksym) != -EBUSY,
1265                                              30 * HZ) <= 0) {
1266                 pr_warn("%s: gave up waiting for init of module %s.\n",
1267                         mod->name, owner);
1268         }
1269         return ksym;
1270 }
1271 
1272 /*
1273  * /sys/module/foo/sections stuff
1274  * J. Corbet <corbet@lwn.net>
1275  */
1276 #ifdef CONFIG_SYSFS
1277 
1278 #ifdef CONFIG_KALLSYMS
1279 static inline bool sect_empty(const Elf_Shdr *sect)
1280 {
1281         return !(sect->sh_flags & SHF_ALLOC) || sect->sh_size == 0;
1282 }
1283 
1284 struct module_sect_attr {
1285         struct module_attribute mattr;
1286         char *name;
1287         unsigned long address;
1288 };
1289 
1290 struct module_sect_attrs {
1291         struct attribute_group grp;
1292         unsigned int nsections;
1293         struct module_sect_attr attrs[0];
1294 };
1295 
1296 static ssize_t module_sect_show(struct module_attribute *mattr,
1297                                 struct module_kobject *mk, char *buf)
1298 {
1299         struct module_sect_attr *sattr =
1300                 container_of(mattr, struct module_sect_attr, mattr);
1301         return sprintf(buf, "0x%pK\n", (void *)sattr->address);
1302 }
1303 
1304 static void free_sect_attrs(struct module_sect_attrs *sect_attrs)
1305 {
1306         unsigned int section;
1307 
1308         for (section = 0; section < sect_attrs->nsections; section++)
1309                 kfree(sect_attrs->attrs[section].name);
1310         kfree(sect_attrs);
1311 }
1312 
1313 static void add_sect_attrs(struct module *mod, const struct load_info *info)
1314 {
1315         unsigned int nloaded = 0, i, size[2];
1316         struct module_sect_attrs *sect_attrs;
1317         struct module_sect_attr *sattr;
1318         struct attribute **gattr;
1319 
1320         /* Count loaded sections and allocate structures */
1321         for (i = 0; i < info->hdr->e_shnum; i++)
1322                 if (!sect_empty(&info->sechdrs[i]))
1323                         nloaded++;
1324         size[0] = ALIGN(sizeof(*sect_attrs)
1325                         + nloaded * sizeof(sect_attrs->attrs[0]),
1326                         sizeof(sect_attrs->grp.attrs[0]));
1327         size[1] = (nloaded + 1) * sizeof(sect_attrs->grp.attrs[0]);
1328         sect_attrs = kzalloc(size[0] + size[1], GFP_KERNEL);
1329         if (sect_attrs == NULL)
1330                 return;
1331 
1332         /* Setup section attributes. */
1333         sect_attrs->grp.name = "sections";
1334         sect_attrs->grp.attrs = (void *)sect_attrs + size[0];
1335 
1336         sect_attrs->nsections = 0;
1337         sattr = &sect_attrs->attrs[0];
1338         gattr = &sect_attrs->grp.attrs[0];
1339         for (i = 0; i < info->hdr->e_shnum; i++) {
1340                 Elf_Shdr *sec = &info->sechdrs[i];
1341                 if (sect_empty(sec))
1342                         continue;
1343                 sattr->address = sec->sh_addr;
1344                 sattr->name = kstrdup(info->secstrings + sec->sh_name,
1345                                         GFP_KERNEL);
1346                 if (sattr->name == NULL)
1347                         goto out;
1348                 sect_attrs->nsections++;
1349                 sysfs_attr_init(&sattr->mattr.attr);
1350                 sattr->mattr.show = module_sect_show;
1351                 sattr->mattr.store = NULL;
1352                 sattr->mattr.attr.name = sattr->name;
1353                 sattr->mattr.attr.mode = S_IRUGO;
1354                 *(gattr++) = &(sattr++)->mattr.attr;
1355         }
1356         *gattr = NULL;
1357 
1358         if (sysfs_create_group(&mod->mkobj.kobj, &sect_attrs->grp))
1359                 goto out;
1360 
1361         mod->sect_attrs = sect_attrs;
1362         return;
1363   out:
1364         free_sect_attrs(sect_attrs);
1365 }
1366 
1367 static void remove_sect_attrs(struct module *mod)
1368 {
1369         if (mod->sect_attrs) {
1370                 sysfs_remove_group(&mod->mkobj.kobj,
1371                                    &mod->sect_attrs->grp);
1372                 /* We are positive that no one is using any sect attrs
1373                  * at this point.  Deallocate immediately. */
1374                 free_sect_attrs(mod->sect_attrs);
1375                 mod->sect_attrs = NULL;
1376         }
1377 }
1378 
1379 /*
1380  * /sys/module/foo/notes/.section.name gives contents of SHT_NOTE sections.
1381  */
1382 
1383 struct module_notes_attrs {
1384         struct kobject *dir;
1385         unsigned int notes;
1386         struct bin_attribute attrs[0];
1387 };
1388 
1389 static ssize_t module_notes_read(struct file *filp, struct kobject *kobj,
1390                                  struct bin_attribute *bin_attr,
1391                                  char *buf, loff_t pos, size_t count)
1392 {
1393         /*
1394          * The caller checked the pos and count against our size.
1395          */
1396         memcpy(buf, bin_attr->private + pos, count);
1397         return count;
1398 }
1399 
1400 static void free_notes_attrs(struct module_notes_attrs *notes_attrs,
1401                              unsigned int i)
1402 {
1403         if (notes_attrs->dir) {
1404                 while (i-- > 0)
1405                         sysfs_remove_bin_file(notes_attrs->dir,
1406                                               &notes_attrs->attrs[i]);
1407                 kobject_put(notes_attrs->dir);
1408         }
1409         kfree(notes_attrs);
1410 }
1411 
1412 static void add_notes_attrs(struct module *mod, const struct load_info *info)
1413 {
1414         unsigned int notes, loaded, i;
1415         struct module_notes_attrs *notes_attrs;
1416         struct bin_attribute *nattr;
1417 
1418         /* failed to create section attributes, so can't create notes */
1419         if (!mod->sect_attrs)
1420                 return;
1421 
1422         /* Count notes sections and allocate structures.  */
1423         notes = 0;
1424         for (i = 0; i < info->hdr->e_shnum; i++)
1425                 if (!sect_empty(&info->sechdrs[i]) &&
1426                     (info->sechdrs[i].sh_type == SHT_NOTE))
1427                         ++notes;
1428 
1429         if (notes == 0)
1430                 return;
1431 
1432         notes_attrs = kzalloc(sizeof(*notes_attrs)
1433                               + notes * sizeof(notes_attrs->attrs[0]),
1434                               GFP_KERNEL);
1435         if (notes_attrs == NULL)
1436                 return;
1437 
1438         notes_attrs->notes = notes;
1439         nattr = &notes_attrs->attrs[0];
1440         for (loaded = i = 0; i < info->hdr->e_shnum; ++i) {
1441                 if (sect_empty(&info->sechdrs[i]))
1442                         continue;
1443                 if (info->sechdrs[i].sh_type == SHT_NOTE) {
1444                         sysfs_bin_attr_init(nattr);
1445                         nattr->attr.name = mod->sect_attrs->attrs[loaded].name;
1446                         nattr->attr.mode = S_IRUGO;
1447                         nattr->size = info->sechdrs[i].sh_size;
1448                         nattr->private = (void *) info->sechdrs[i].sh_addr;
1449                         nattr->read = module_notes_read;
1450                         ++nattr;
1451                 }
1452                 ++loaded;
1453         }
1454 
1455         notes_attrs->dir = kobject_create_and_add("notes", &mod->mkobj.kobj);
1456         if (!notes_attrs->dir)
1457                 goto out;
1458 
1459         for (i = 0; i < notes; ++i)
1460                 if (sysfs_create_bin_file(notes_attrs->dir,
1461                                           &notes_attrs->attrs[i]))
1462                         goto out;
1463 
1464         mod->notes_attrs = notes_attrs;
1465         return;
1466 
1467   out:
1468         free_notes_attrs(notes_attrs, i);
1469 }
1470 
1471 static void remove_notes_attrs(struct module *mod)
1472 {
1473         if (mod->notes_attrs)
1474                 free_notes_attrs(mod->notes_attrs, mod->notes_attrs->notes);
1475 }
1476 
1477 #else
1478 
1479 static inline void add_sect_attrs(struct module *mod,
1480                                   const struct load_info *info)
1481 {
1482 }
1483 
1484 static inline void remove_sect_attrs(struct module *mod)
1485 {
1486 }
1487 
1488 static inline void add_notes_attrs(struct module *mod,
1489                                    const struct load_info *info)
1490 {
1491 }
1492 
1493 static inline void remove_notes_attrs(struct module *mod)
1494 {
1495 }
1496 #endif /* CONFIG_KALLSYMS */
1497 
1498 static void add_usage_links(struct module *mod)
1499 {
1500 #ifdef CONFIG_MODULE_UNLOAD
1501         struct module_use *use;
1502         int nowarn;
1503 
1504         mutex_lock(&module_mutex);
1505         list_for_each_entry(use, &mod->target_list, target_list) {
1506                 nowarn = sysfs_create_link(use->target->holders_dir,
1507                                            &mod->mkobj.kobj, mod->name);
1508         }
1509         mutex_unlock(&module_mutex);
1510 #endif
1511 }
1512 
1513 static void del_usage_links(struct module *mod)
1514 {
1515 #ifdef CONFIG_MODULE_UNLOAD
1516         struct module_use *use;
1517 
1518         mutex_lock(&module_mutex);
1519         list_for_each_entry(use, &mod->target_list, target_list)
1520                 sysfs_remove_link(use->target->holders_dir, mod->name);
1521         mutex_unlock(&module_mutex);
1522 #endif
1523 }
1524 
1525 static int module_add_modinfo_attrs(struct module *mod)
1526 {
1527         struct module_attribute *attr;
1528         struct module_attribute *temp_attr;
1529         int error = 0;
1530         int i;
1531 
1532         mod->modinfo_attrs = kzalloc((sizeof(struct module_attribute) *
1533                                         (ARRAY_SIZE(modinfo_attrs) + 1)),
1534                                         GFP_KERNEL);
1535         if (!mod->modinfo_attrs)
1536                 return -ENOMEM;
1537 
1538         temp_attr = mod->modinfo_attrs;
1539         for (i = 0; (attr = modinfo_attrs[i]) && !error; i++) {
1540                 if (!attr->test ||
1541                     (attr->test && attr->test(mod))) {
1542                         memcpy(temp_attr, attr, sizeof(*temp_attr));
1543                         sysfs_attr_init(&temp_attr->attr);
1544                         error = sysfs_create_file(&mod->mkobj.kobj,
1545                                         &temp_attr->attr);
1546                         ++temp_attr;
1547                 }
1548         }
1549         return error;
1550 }
1551 
1552 static void module_remove_modinfo_attrs(struct module *mod)
1553 {
1554         struct module_attribute *attr;
1555         int i;
1556 
1557         for (i = 0; (attr = &mod->modinfo_attrs[i]); i++) {
1558                 /* pick a field to test for end of list */
1559                 if (!attr->attr.name)
1560                         break;
1561                 sysfs_remove_file(&mod->mkobj.kobj, &attr->attr);
1562                 if (attr->free)
1563                         attr->free(mod);
1564         }
1565         kfree(mod->modinfo_attrs);
1566 }
1567 
1568 static void mod_kobject_put(struct module *mod)
1569 {
1570         DECLARE_COMPLETION_ONSTACK(c);
1571         mod->mkobj.kobj_completion = &c;
1572         kobject_put(&mod->mkobj.kobj);
1573         wait_for_completion(&c);
1574 }
1575 
1576 static int mod_sysfs_init(struct module *mod)
1577 {
1578         int err;
1579         struct kobject *kobj;
1580 
1581         if (!module_sysfs_initialized) {
1582                 pr_err("%s: module sysfs not initialized\n", mod->name);
1583                 err = -EINVAL;
1584                 goto out;
1585         }
1586 
1587         kobj = kset_find_obj(module_kset, mod->name);
1588         if (kobj) {
1589                 pr_err("%s: module is already loaded\n", mod->name);
1590                 kobject_put(kobj);
1591                 err = -EINVAL;
1592                 goto out;
1593         }
1594 
1595         mod->mkobj.mod = mod;
1596 
1597         memset(&mod->mkobj.kobj, 0, sizeof(mod->mkobj.kobj));
1598         mod->mkobj.kobj.kset = module_kset;
1599         err = kobject_init_and_add(&mod->mkobj.kobj, &module_ktype, NULL,
1600                                    "%s", mod->name);
1601         if (err)
1602                 mod_kobject_put(mod);
1603 
1604         /* delay uevent until full sysfs population */
1605 out:
1606         return err;
1607 }
1608 
1609 static int mod_sysfs_setup(struct module *mod,
1610                            const struct load_info *info,
1611                            struct kernel_param *kparam,
1612                            unsigned int num_params)
1613 {
1614         int err;
1615 
1616         err = mod_sysfs_init(mod);
1617         if (err)
1618                 goto out;
1619 
1620         mod->holders_dir = kobject_create_and_add("holders", &mod->mkobj.kobj);
1621         if (!mod->holders_dir) {
1622                 err = -ENOMEM;
1623                 goto out_unreg;
1624         }
1625 
1626         err = module_param_sysfs_setup(mod, kparam, num_params);
1627         if (err)
1628                 goto out_unreg_holders;
1629 
1630         err = module_add_modinfo_attrs(mod);
1631         if (err)
1632                 goto out_unreg_param;
1633 
1634         add_usage_links(mod);
1635         add_sect_attrs(mod, info);
1636         add_notes_attrs(mod, info);
1637 
1638         kobject_uevent(&mod->mkobj.kobj, KOBJ_ADD);
1639         return 0;
1640 
1641 out_unreg_param:
1642         module_param_sysfs_remove(mod);
1643 out_unreg_holders:
1644         kobject_put(mod->holders_dir);
1645 out_unreg:
1646         mod_kobject_put(mod);
1647 out:
1648         return err;
1649 }
1650 
1651 static void mod_sysfs_fini(struct module *mod)
1652 {
1653         remove_notes_attrs(mod);
1654         remove_sect_attrs(mod);
1655         mod_kobject_put(mod);
1656 }
1657 
1658 #else /* !CONFIG_SYSFS */
1659 
1660 static int mod_sysfs_setup(struct module *mod,
1661                            const struct load_info *info,
1662                            struct kernel_param *kparam,
1663                            unsigned int num_params)
1664 {
1665         return 0;
1666 }
1667 
1668 static void mod_sysfs_fini(struct module *mod)
1669 {
1670 }
1671 
1672 static void module_remove_modinfo_attrs(struct module *mod)
1673 {
1674 }
1675 
1676 static void del_usage_links(struct module *mod)
1677 {
1678 }
1679 
1680 #endif /* CONFIG_SYSFS */
1681 
1682 static void mod_sysfs_teardown(struct module *mod)
1683 {
1684         del_usage_links(mod);
1685         module_remove_modinfo_attrs(mod);
1686         module_param_sysfs_remove(mod);
1687         kobject_put(mod->mkobj.drivers_dir);
1688         kobject_put(mod->holders_dir);
1689         mod_sysfs_fini(mod);
1690 }
1691 
1692 #ifdef CONFIG_DEBUG_SET_MODULE_RONX
1693 /*
1694  * LKM RO/NX protection: protect module's text/ro-data
1695  * from modification and any data from execution.
1696  */
1697 void set_page_attributes(void *start, void *end, int (*set)(unsigned long start, int num_pages))
1698 {
1699         unsigned long begin_pfn = PFN_DOWN((unsigned long)start);
1700         unsigned long end_pfn = PFN_DOWN((unsigned long)end);
1701 
1702         if (end_pfn > begin_pfn)
1703                 set(begin_pfn << PAGE_SHIFT, end_pfn - begin_pfn);
1704 }
1705 
1706 static void set_section_ro_nx(void *base,
1707                         unsigned long text_size,
1708                         unsigned long ro_size,
1709                         unsigned long total_size)
1710 {
1711         /* begin and end PFNs of the current subsection */
1712         unsigned long begin_pfn;
1713         unsigned long end_pfn;
1714 
1715         /*
1716          * Set RO for module text and RO-data:
1717          * - Always protect first page.
1718          * - Do not protect last partial page.
1719          */
1720         if (ro_size > 0)
1721                 set_page_attributes(base, base + ro_size, set_memory_ro);
1722 
1723         /*
1724          * Set NX permissions for module data:
1725          * - Do not protect first partial page.
1726          * - Always protect last page.
1727          */
1728         if (total_size > text_size) {
1729                 begin_pfn = PFN_UP((unsigned long)base + text_size);
1730                 end_pfn = PFN_UP((unsigned long)base + total_size);
1731                 if (end_pfn > begin_pfn)
1732                         set_memory_nx(begin_pfn << PAGE_SHIFT, end_pfn - begin_pfn);
1733         }
1734 }
1735 
1736 static void unset_module_core_ro_nx(struct module *mod)
1737 {
1738         set_page_attributes(mod->module_core + mod->core_text_size,
1739                 mod->module_core + mod->core_size,
1740                 set_memory_x);
1741         set_page_attributes(mod->module_core,
1742                 mod->module_core + mod->core_ro_size,
1743                 set_memory_rw);
1744 }
1745 
1746 static void unset_module_init_ro_nx(struct module *mod)
1747 {
1748         set_page_attributes(mod->module_init + mod->init_text_size,
1749                 mod->module_init + mod->init_size,
1750                 set_memory_x);
1751         set_page_attributes(mod->module_init,
1752                 mod->module_init + mod->init_ro_size,
1753                 set_memory_rw);
1754 }
1755 
1756 /* Iterate through all modules and set each module's text as RW */
1757 void set_all_modules_text_rw(void)
1758 {
1759         struct module *mod;
1760 
1761         mutex_lock(&module_mutex);
1762         list_for_each_entry_rcu(mod, &modules, list) {
1763                 if (mod->state == MODULE_STATE_UNFORMED)
1764                         continue;
1765                 if ((mod->module_core) && (mod->core_text_size)) {
1766                         set_page_attributes(mod->module_core,
1767                                                 mod->module_core + mod->core_text_size,
1768                                                 set_memory_rw);
1769                 }
1770                 if ((mod->module_init) && (mod->init_text_size)) {
1771                         set_page_attributes(mod->module_init,
1772                                                 mod->module_init + mod->init_text_size,
1773                                                 set_memory_rw);
1774                 }
1775         }
1776         mutex_unlock(&module_mutex);
1777 }
1778 
1779 /* Iterate through all modules and set each module's text as RO */
1780 void set_all_modules_text_ro(void)
1781 {
1782         struct module *mod;
1783 
1784         mutex_lock(&module_mutex);
1785         list_for_each_entry_rcu(mod, &modules, list) {
1786                 if (mod->state == MODULE_STATE_UNFORMED)
1787                         continue;
1788                 if ((mod->module_core) && (mod->core_text_size)) {
1789                         set_page_attributes(mod->module_core,
1790                                                 mod->module_core + mod->core_text_size,
1791                                                 set_memory_ro);
1792                 }
1793                 if ((mod->module_init) && (mod->init_text_size)) {
1794                         set_page_attributes(mod->module_init,
1795                                                 mod->module_init + mod->init_text_size,
1796                                                 set_memory_ro);
1797                 }
1798         }
1799         mutex_unlock(&module_mutex);
1800 }
1801 #else
1802 static inline void set_section_ro_nx(void *base, unsigned long text_size, unsigned long ro_size, unsigned long total_size) { }
1803 static void unset_module_core_ro_nx(struct module *mod) { }
1804 static void unset_module_init_ro_nx(struct module *mod) { }
1805 #endif
1806 
1807 void __weak module_memfree(void *module_region)
1808 {
1809         vfree(module_region);
1810 }
1811 
1812 void __weak module_arch_cleanup(struct module *mod)
1813 {
1814 }
1815 
1816 void __weak module_arch_freeing_init(struct module *mod)
1817 {
1818 }
1819 
1820 /* Free a module, remove from lists, etc. */
1821 static void free_module(struct module *mod)
1822 {
1823         trace_module_free(mod);
1824 
1825         mod_sysfs_teardown(mod);
1826 
1827         /* We leave it in list to prevent duplicate loads, but make sure
1828          * that noone uses it while it's being deconstructed. */
1829         mutex_lock(&module_mutex);
1830         mod->state = MODULE_STATE_UNFORMED;
1831         mutex_unlock(&module_mutex);
1832 
1833         /* Remove dynamic debug info */
1834         ddebug_remove_module(mod->name);
1835 
1836         /* Arch-specific cleanup. */
1837         module_arch_cleanup(mod);
1838 
1839         /* Module unload stuff */
1840         module_unload_free(mod);
1841 
1842         /* Free any allocated parameters. */
1843         destroy_params(mod->kp, mod->num_kp);
1844 
1845         /* Now we can delete it from the lists */
1846         mutex_lock(&module_mutex);
1847         /* Unlink carefully: kallsyms could be walking list. */
1848         list_del_rcu(&mod->list);
1849         /* Remove this module from bug list, this uses list_del_rcu */
1850         module_bug_cleanup(mod);
1851         /* Wait for RCU synchronizing before releasing mod->list and buglist. */
1852         synchronize_rcu();
1853         mutex_unlock(&module_mutex);
1854 
1855         /* This may be NULL, but that's OK */
1856         unset_module_init_ro_nx(mod);
1857         module_arch_freeing_init(mod);
1858         module_memfree(mod->module_init);
1859         kfree(mod->args);
1860         percpu_modfree(mod);
1861 
1862         /* Free lock-classes: */
1863         lockdep_free_key_range(mod->module_core, mod->core_size);
1864 
1865         /* Finally, free the core (containing the module structure) */
1866         unset_module_core_ro_nx(mod);
1867         module_memfree(mod->module_core);
1868 
1869 #ifdef CONFIG_MPU
1870         update_protections(current->mm);
1871 #endif
1872 }
1873 
1874 void *__symbol_get(const char *symbol)
1875 {
1876         struct module *owner;
1877         const struct kernel_symbol *sym;
1878 
1879         preempt_disable();
1880         sym = find_symbol(symbol, &owner, NULL, true, true);
1881         if (sym && strong_try_module_get(owner))
1882                 sym = NULL;
1883         preempt_enable();
1884 
1885         return sym ? (void *)sym->value : NULL;
1886 }
1887 EXPORT_SYMBOL_GPL(__symbol_get);
1888 
1889 /*
1890  * Ensure that an exported symbol [global namespace] does not already exist
1891  * in the kernel or in some other module's exported symbol table.
1892  *
1893  * You must hold the module_mutex.
1894  */
1895 static int verify_export_symbols(struct module *mod)
1896 {
1897         unsigned int i;
1898         struct module *owner;
1899         const struct kernel_symbol *s;
1900         struct {
1901                 const struct kernel_symbol *sym;
1902                 unsigned int num;
1903         } arr[] = {
1904                 { mod->syms, mod->num_syms },
1905                 { mod->gpl_syms, mod->num_gpl_syms },
1906                 { mod->gpl_future_syms, mod->num_gpl_future_syms },
1907 #ifdef CONFIG_UNUSED_SYMBOLS
1908                 { mod->unused_syms, mod->num_unused_syms },
1909                 { mod->unused_gpl_syms, mod->num_unused_gpl_syms },
1910 #endif
1911         };
1912 
1913         for (i = 0; i < ARRAY_SIZE(arr); i++) {
1914                 for (s = arr[i].sym; s < arr[i].sym + arr[i].num; s++) {
1915                         if (find_symbol(s->name, &owner, NULL, true, false)) {
1916                                 pr_err("%s: exports duplicate symbol %s"
1917                                        " (owned by %s)\n",
1918                                        mod->name, s->name, module_name(owner));
1919                                 return -ENOEXEC;
1920                         }
1921                 }
1922         }
1923         return 0;
1924 }
1925 
1926 /* Change all symbols so that st_value encodes the pointer directly. */
1927 static int simplify_symbols(struct module *mod, const struct load_info *info)
1928 {
1929         Elf_Shdr *symsec = &info->sechdrs[info->index.sym];
1930         Elf_Sym *sym = (void *)symsec->sh_addr;
1931         unsigned long secbase;
1932         unsigned int i;
1933         int ret = 0;
1934         const struct kernel_symbol *ksym;
1935 
1936         for (i = 1; i < symsec->sh_size / sizeof(Elf_Sym); i++) {
1937                 const char *name = info->strtab + sym[i].st_name;
1938 
1939                 switch (sym[i].st_shndx) {
1940                 case SHN_COMMON:
1941                         /* Ignore common symbols */
1942                         if (!strncmp(name, "__gnu_lto", 9))
1943                                 break;
1944 
1945                         /* We compiled with -fno-common.  These are not
1946                            supposed to happen.  */
1947                         pr_debug("Common symbol: %s\n", name);
1948                         pr_warn("%s: please compile with -fno-common\n",
1949                                mod->name);
1950                         ret = -ENOEXEC;
1951                         break;
1952 
1953                 case SHN_ABS:
1954                         /* Don't need to do anything */
1955                         pr_debug("Absolute symbol: 0x%08lx\n",
1956                                (long)sym[i].st_value);
1957                         break;
1958 
1959                 case SHN_UNDEF:
1960                         ksym = resolve_symbol_wait(mod, info, name);
1961                         /* Ok if resolved.  */
1962                         if (ksym && !IS_ERR(ksym)) {
1963                                 sym[i].st_value = ksym->value;
1964                                 break;
1965                         }
1966 
1967                         /* Ok if weak.  */
1968                         if (!ksym && ELF_ST_BIND(sym[i].st_info) == STB_WEAK)
1969                                 break;
1970 
1971                         pr_warn("%s: Unknown symbol %s (err %li)\n",
1972                                 mod->name, name, PTR_ERR(ksym));
1973                         ret = PTR_ERR(ksym) ?: -ENOENT;
1974                         break;
1975 
1976                 default:
1977                         /* Divert to percpu allocation if a percpu var. */
1978                         if (sym[i].st_shndx == info->index.pcpu)
1979                                 secbase = (unsigned long)mod_percpu(mod);
1980                         else
1981                                 secbase = info->sechdrs[sym[i].st_shndx].sh_addr;
1982                         sym[i].st_value += secbase;
1983                         break;
1984                 }
1985         }
1986 
1987         return ret;
1988 }
1989 
1990 static int apply_relocations(struct module *mod, const struct load_info *info)
1991 {
1992         unsigned int i;
1993         int err = 0;
1994 
1995         /* Now do relocations. */
1996         for (i = 1; i < info->hdr->e_shnum; i++) {
1997                 unsigned int infosec = info->sechdrs[i].sh_info;
1998 
1999                 /* Not a valid relocation section? */
2000                 if (infosec >= info->hdr->e_shnum)
2001                         continue;
2002 
2003                 /* Don't bother with non-allocated sections */
2004                 if (!(info->sechdrs[infosec].sh_flags & SHF_ALLOC))
2005                         continue;
2006 
2007                 if (info->sechdrs[i].sh_type == SHT_REL)
2008                         err = apply_relocate(info->sechdrs, info->strtab,
2009                                              info->index.sym, i, mod);
2010                 else if (info->sechdrs[i].sh_type == SHT_RELA)
2011                         err = apply_relocate_add(info->sechdrs, info->strtab,
2012                                                  info->index.sym, i, mod);
2013                 if (err < 0)
2014                         break;
2015         }
2016         return err;
2017 }
2018 
2019 /* Additional bytes needed by arch in front of individual sections */
2020 unsigned int __weak arch_mod_section_prepend(struct module *mod,
2021                                              unsigned int section)
2022 {
2023         /* default implementation just returns zero */
2024         return 0;
2025 }
2026 
2027 /* Update size with this section: return offset. */
2028 static long get_offset(struct module *mod, unsigned int *size,
2029                        Elf_Shdr *sechdr, unsigned int section)
2030 {
2031         long ret;
2032 
2033         *size += arch_mod_section_prepend(mod, section);
2034         ret = ALIGN(*size, sechdr->sh_addralign ?: 1);
2035         *size = ret + sechdr->sh_size;
2036         return ret;
2037 }
2038 
2039 /* Lay out the SHF_ALLOC sections in a way not dissimilar to how ld
2040    might -- code, read-only data, read-write data, small data.  Tally
2041    sizes, and place the offsets into sh_entsize fields: high bit means it
2042    belongs in init. */
2043 static void layout_sections(struct module *mod, struct load_info *info)
2044 {
2045         static unsigned long const masks[][2] = {
2046                 /* NOTE: all executable code must be the first section
2047                  * in this array; otherwise modify the text_size
2048                  * finder in the two loops below */
2049                 { SHF_EXECINSTR | SHF_ALLOC, ARCH_SHF_SMALL },
2050                 { SHF_ALLOC, SHF_WRITE | ARCH_SHF_SMALL },
2051                 { SHF_WRITE | SHF_ALLOC, ARCH_SHF_SMALL },
2052                 { ARCH_SHF_SMALL | SHF_ALLOC, 0 }
2053         };
2054         unsigned int m, i;
2055 
2056         for (i = 0; i < info->hdr->e_shnum; i++)
2057                 info->sechdrs[i].sh_entsize = ~0UL;
2058 
2059         pr_debug("Core section allocation order:\n");
2060         for (m = 0; m < ARRAY_SIZE(masks); ++m) {
2061                 for (i = 0; i < info->hdr->e_shnum; ++i) {
2062                         Elf_Shdr *s = &info->sechdrs[i];
2063                         const char *sname = info->secstrings + s->sh_name;
2064 
2065                         if ((s->sh_flags & masks[m][0]) != masks[m][0]
2066                             || (s->sh_flags & masks[m][1])
2067                             || s->sh_entsize != ~0UL
2068                             || strstarts(sname, ".init"))
2069                                 continue;
2070                         s->sh_entsize = get_offset(mod, &mod->core_size, s, i);
2071                         pr_debug("\t%s\n", sname);
2072                 }
2073                 switch (m) {
2074                 case 0: /* executable */
2075                         mod->core_size = debug_align(mod->core_size);
2076                         mod->core_text_size = mod->core_size;
2077                         break;
2078                 case 1: /* RO: text and ro-data */
2079                         mod->core_size = debug_align(mod->core_size);
2080                         mod->core_ro_size = mod->core_size;
2081                         break;
2082                 case 3: /* whole core */
2083                         mod->core_size = debug_align(mod->core_size);
2084                         break;
2085                 }
2086         }
2087 
2088         pr_debug("Init section allocation order:\n");
2089         for (m = 0; m < ARRAY_SIZE(masks); ++m) {
2090                 for (i = 0; i < info->hdr->e_shnum; ++i) {
2091                         Elf_Shdr *s = &info->sechdrs[i];
2092                         const char *sname = info->secstrings + s->sh_name;
2093 
2094                         if ((s->sh_flags & masks[m][0]) != masks[m][0]
2095                             || (s->sh_flags & masks[m][1])
2096                             || s->sh_entsize != ~0UL
2097                             || !strstarts(sname, ".init"))
2098                                 continue;
2099                         s->sh_entsize = (get_offset(mod, &mod->init_size, s, i)
2100                                          | INIT_OFFSET_MASK);
2101                         pr_debug("\t%s\n", sname);
2102                 }
2103                 switch (m) {
2104                 case 0: /* executable */
2105                         mod->init_size = debug_align(mod->init_size);
2106                         mod->init_text_size = mod->init_size;
2107                         break;
2108                 case 1: /* RO: text and ro-data */
2109                         mod->init_size = debug_align(mod->init_size);
2110                         mod->init_ro_size = mod->init_size;
2111                         break;
2112                 case 3: /* whole init */
2113                         mod->init_size = debug_align(mod->init_size);
2114                         break;
2115                 }
2116         }
2117 }
2118 
2119 static void set_license(struct module *mod, const char *license)
2120 {
2121         if (!license)
2122                 license = "unspecified";
2123 
2124         if (!license_is_gpl_compatible(license)) {
2125                 if (!test_taint(TAINT_PROPRIETARY_MODULE))
2126                         pr_warn("%s: module license '%s' taints kernel.\n",
2127                                 mod->name, license);
2128                 add_taint_module(mod, TAINT_PROPRIETARY_MODULE,
2129                                  LOCKDEP_NOW_UNRELIABLE);
2130         }
2131 }
2132 
2133 /* Parse tag=value strings from .modinfo section */
2134 static char *next_string(char *string, unsigned long *secsize)
2135 {
2136         /* Skip non-zero chars */
2137         while (string[0]) {
2138                 string++;
2139                 if ((*secsize)-- <= 1)
2140                         return NULL;
2141         }
2142 
2143         /* Skip any zero padding. */
2144         while (!string[0]) {
2145                 string++;
2146                 if ((*secsize)-- <= 1)
2147                         return NULL;
2148         }
2149         return string;
2150 }
2151 
2152 static char *get_modinfo(struct load_info *info, const char *tag)
2153 {
2154         char *p;
2155         unsigned int taglen = strlen(tag);
2156         Elf_Shdr *infosec = &info->sechdrs[info->index.info];
2157         unsigned long size = infosec->sh_size;
2158 
2159         for (p = (char *)infosec->sh_addr; p; p = next_string(p, &size)) {
2160                 if (strncmp(p, tag, taglen) == 0 && p[taglen] == '=')
2161                         return p + taglen + 1;
2162         }
2163         return NULL;
2164 }
2165 
2166 static void setup_modinfo(struct module *mod, struct load_info *info)
2167 {
2168         struct module_attribute *attr;
2169         int i;
2170 
2171         for (i = 0; (attr = modinfo_attrs[i]); i++) {
2172                 if (attr->setup)
2173                         attr->setup(mod, get_modinfo(info, attr->attr.name));
2174         }
2175 }
2176 
2177 static void free_modinfo(struct module *mod)
2178 {
2179         struct module_attribute *attr;
2180         int i;
2181 
2182         for (i = 0; (attr = modinfo_attrs[i]); i++) {
2183                 if (attr->free)
2184                         attr->free(mod);
2185         }
2186 }
2187 
2188 #ifdef CONFIG_KALLSYMS
2189 
2190 /* lookup symbol in given range of kernel_symbols */
2191 static const struct kernel_symbol *lookup_symbol(const char *name,
2192         const struct kernel_symbol *start,
2193         const struct kernel_symbol *stop)
2194 {
2195         return bsearch(name, start, stop - start,
2196                         sizeof(struct kernel_symbol), cmp_name);
2197 }
2198 
2199 static int is_exported(const char *name, unsigned long value,
2200                        const struct module *mod)
2201 {
2202         const struct kernel_symbol *ks;
2203         if (!mod)
2204                 ks = lookup_symbol(name, __start___ksymtab, __stop___ksymtab);
2205         else
2206                 ks = lookup_symbol(name, mod->syms, mod->syms + mod->num_syms);
2207         return ks != NULL && ks->value == value;
2208 }
2209 
2210 /* As per nm */
2211 static char elf_type(const Elf_Sym *sym, const struct load_info *info)
2212 {
2213         const Elf_Shdr *sechdrs = info->sechdrs;
2214 
2215         if (ELF_ST_BIND(sym->st_info) == STB_WEAK) {
2216                 if (ELF_ST_TYPE(sym->st_info) == STT_OBJECT)
2217                         return 'v';
2218                 else
2219                         return 'w';
2220         }
2221         if (sym->st_shndx == SHN_UNDEF)
2222                 return 'U';
2223         if (sym->st_shndx == SHN_ABS)
2224                 return 'a';
2225         if (sym->st_shndx >= SHN_LORESERVE)
2226                 return '?';
2227         if (sechdrs[sym->st_shndx].sh_flags & SHF_EXECINSTR)
2228                 return 't';
2229         if (sechdrs[sym->st_shndx].sh_flags & SHF_ALLOC
2230             && sechdrs[sym->st_shndx].sh_type != SHT_NOBITS) {
2231                 if (!(sechdrs[sym->st_shndx].sh_flags & SHF_WRITE))
2232                         return 'r';
2233                 else if (sechdrs[sym->st_shndx].sh_flags & ARCH_SHF_SMALL)
2234                         return 'g';
2235                 else
2236                         return 'd';
2237         }
2238         if (sechdrs[sym->st_shndx].sh_type == SHT_NOBITS) {
2239                 if (sechdrs[sym->st_shndx].sh_flags & ARCH_SHF_SMALL)
2240                         return 's';
2241                 else
2242                         return 'b';
2243         }
2244         if (strstarts(info->secstrings + sechdrs[sym->st_shndx].sh_name,
2245                       ".debug")) {
2246                 return 'n';
2247         }
2248         return '?';
2249 }
2250 
2251 static bool is_core_symbol(const Elf_Sym *src, const Elf_Shdr *sechdrs,
2252                         unsigned int shnum)
2253 {
2254         const Elf_Shdr *sec;
2255 
2256         if (src->st_shndx == SHN_UNDEF
2257             || src->st_shndx >= shnum
2258             || !src->st_name)
2259                 return false;
2260 
2261         sec = sechdrs + src->st_shndx;
2262         if (!(sec->sh_flags & SHF_ALLOC)
2263 #ifndef CONFIG_KALLSYMS_ALL
2264             || !(sec->sh_flags & SHF_EXECINSTR)
2265 #endif
2266             || (sec->sh_entsize & INIT_OFFSET_MASK))
2267                 return false;
2268 
2269         return true;
2270 }
2271 
2272 /*
2273  * We only allocate and copy the strings needed by the parts of symtab
2274  * we keep.  This is simple, but has the effect of making multiple
2275  * copies of duplicates.  We could be more sophisticated, see
2276  * linux-kernel thread starting with
2277  * <73defb5e4bca04a6431392cc341112b1@localhost>.
2278  */
2279 static void layout_symtab(struct module *mod, struct load_info *info)
2280 {
2281         Elf_Shdr *symsect = info->sechdrs + info->index.sym;
2282         Elf_Shdr *strsect = info->sechdrs + info->index.str;
2283         const Elf_Sym *src;
2284         unsigned int i, nsrc, ndst, strtab_size = 0;
2285 
2286         /* Put symbol section at end of init part of module. */
2287         symsect->sh_flags |= SHF_ALLOC;
2288         symsect->sh_entsize = get_offset(mod, &mod->init_size, symsect,
2289                                          info->index.sym) | INIT_OFFSET_MASK;
2290         pr_debug("\t%s\n", info->secstrings + symsect->sh_name);
2291 
2292         src = (void *)info->hdr + symsect->sh_offset;
2293         nsrc = symsect->sh_size / sizeof(*src);
2294 
2295         /* Compute total space required for the core symbols' strtab. */
2296         for (ndst = i = 0; i < nsrc; i++) {
2297                 if (i == 0 ||
2298                     is_core_symbol(src+i, info->sechdrs, info->hdr->e_shnum)) {
2299                         strtab_size += strlen(&info->strtab[src[i].st_name])+1;
2300                         ndst++;
2301                 }
2302         }
2303 
2304         /* Append room for core symbols at end of core part. */
2305         info->symoffs = ALIGN(mod->core_size, symsect->sh_addralign ?: 1);
2306         info->stroffs = mod->core_size = info->symoffs + ndst * sizeof(Elf_Sym);
2307         mod->core_size += strtab_size;
2308 
2309         /* Put string table section at end of init part of module. */
2310         strsect->sh_flags |= SHF_ALLOC;
2311         strsect->sh_entsize = get_offset(mod, &mod->init_size, strsect,
2312                                          info->index.str) | INIT_OFFSET_MASK;
2313         pr_debug("\t%s\n", info->secstrings + strsect->sh_name);
2314 }
2315 
2316 static void add_kallsyms(struct module *mod, const struct load_info *info)
2317 {
2318         unsigned int i, ndst;
2319         const Elf_Sym *src;
2320         Elf_Sym *dst;
2321         char *s;
2322         Elf_Shdr *symsec = &info->sechdrs[info->index.sym];
2323 
2324         mod->symtab = (void *)symsec->sh_addr;
2325         mod->num_symtab = symsec->sh_size / sizeof(Elf_Sym);
2326         /* Make sure we get permanent strtab: don't use info->strtab. */
2327         mod->strtab = (void *)info->sechdrs[info->index.str].sh_addr;
2328 
2329         /* Set types up while we still have access to sections. */
2330         for (i = 0; i < mod->num_symtab; i++)
2331                 mod->symtab[i].st_info = elf_type(&mod->symtab[i], info);
2332 
2333         mod->core_symtab = dst = mod->module_core + info->symoffs;
2334         mod->core_strtab = s = mod->module_core + info->stroffs;
2335         src = mod->symtab;
2336         for (ndst = i = 0; i < mod->num_symtab; i++) {
2337                 if (i == 0 ||
2338                     is_core_symbol(src+i, info->sechdrs, info->hdr->e_shnum)) {
2339                         dst[ndst] = src[i];
2340                         dst[ndst++].st_name = s - mod->core_strtab;
2341                         s += strlcpy(s, &mod->strtab[src[i].st_name],
2342                                      KSYM_NAME_LEN) + 1;
2343                 }
2344         }
2345         mod->core_num_syms = ndst;
2346 }
2347 #else
2348 static inline void layout_symtab(struct module *mod, struct load_info *info)
2349 {
2350 }
2351 
2352 static void add_kallsyms(struct module *mod, const struct load_info *info)
2353 {
2354 }
2355 #endif /* CONFIG_KALLSYMS */
2356 
2357 static void dynamic_debug_setup(struct _ddebug *debug, unsigned int num)
2358 {
2359         if (!debug)
2360                 return;
2361 #ifdef CONFIG_DYNAMIC_DEBUG
2362         if (ddebug_add_module(debug, num, debug->modname))
2363                 pr_err("dynamic debug error adding module: %s\n",
2364                         debug->modname);
2365 #endif
2366 }
2367 
2368 static void dynamic_debug_remove(struct _ddebug *debug)
2369 {
2370         if (debug)
2371                 ddebug_remove_module(debug->modname);
2372 }
2373 
2374 void * __weak module_alloc(unsigned long size)
2375 {
2376         return vmalloc_exec(size);
2377 }
2378 
2379 static void *module_alloc_update_bounds(unsigned long size)
2380 {
2381         void *ret = module_alloc(size);
2382 
2383         if (ret) {
2384                 mutex_lock(&module_mutex);
2385                 /* Update module bounds. */
2386                 if ((unsigned long)ret < module_addr_min)
2387                         module_addr_min = (unsigned long)ret;
2388                 if ((unsigned long)ret + size > module_addr_max)
2389                         module_addr_max = (unsigned long)ret + size;
2390                 mutex_unlock(&module_mutex);
2391         }
2392         return ret;
2393 }
2394 
2395 #ifdef CONFIG_DEBUG_KMEMLEAK
2396 static void kmemleak_load_module(const struct module *mod,
2397                                  const struct load_info *info)
2398 {
2399         unsigned int i;
2400 
2401         /* only scan the sections containing data */
2402         kmemleak_scan_area(mod, sizeof(struct module), GFP_KERNEL);
2403 
2404         for (i = 1; i < info->hdr->e_shnum; i++) {
2405                 /* Scan all writable sections that's not executable */
2406                 if (!(info->sechdrs[i].sh_flags & SHF_ALLOC) ||
2407                     !(info->sechdrs[i].sh_flags & SHF_WRITE) ||
2408                     (info->sechdrs[i].sh_flags & SHF_EXECINSTR))
2409                         continue;
2410 
2411                 kmemleak_scan_area((void *)info->sechdrs[i].sh_addr,
2412                                    info->sechdrs[i].sh_size, GFP_KERNEL);
2413         }
2414 }
2415 #else
2416 static inline void kmemleak_load_module(const struct module *mod,
2417                                         const struct load_info *info)
2418 {
2419 }
2420 #endif
2421 
2422 #ifdef CONFIG_MODULE_SIG
2423 static int module_sig_check(struct load_info *info)
2424 {
2425         int err = -ENOKEY;
2426         const unsigned long markerlen = sizeof(MODULE_SIG_STRING) - 1;
2427         const void *mod = info->hdr;
2428 
2429         if (info->len > markerlen &&
2430             memcmp(mod + info->len - markerlen, MODULE_SIG_STRING, markerlen) == 0) {
2431                 /* We truncate the module to discard the signature */
2432                 info->len -= markerlen;
2433                 err = mod_verify_sig(mod, &info->len);
2434         }
2435 
2436         if (!err) {
2437                 info->sig_ok = true;
2438                 return 0;
2439         }
2440 
2441         /* Not having a signature is only an error if we're strict. */
2442         if (err == -ENOKEY && !sig_enforce)
2443                 err = 0;
2444 
2445         return err;
2446 }
2447 #else /* !CONFIG_MODULE_SIG */
2448 static int module_sig_check(struct load_info *info)
2449 {
2450         return 0;
2451 }
2452 #endif /* !CONFIG_MODULE_SIG */
2453 
2454 /* Sanity checks against invalid binaries, wrong arch, weird elf version. */
2455 static int elf_header_check(struct load_info *info)
2456 {
2457         if (info->len < sizeof(*(info->hdr)))
2458                 return -ENOEXEC;
2459 
2460         if (memcmp(info->hdr->e_ident, ELFMAG, SELFMAG) != 0
2461             || info->hdr->e_type != ET_REL
2462             || !elf_check_arch(info->hdr)
2463             || info->hdr->e_shentsize != sizeof(Elf_Shdr))
2464                 return -ENOEXEC;
2465 
2466         if (info->hdr->e_shoff >= info->len
2467             || (info->hdr->e_shnum * sizeof(Elf_Shdr) >
2468                 info->len - info->hdr->e_shoff))
2469                 return -ENOEXEC;
2470 
2471         return 0;
2472 }
2473 
2474 /* Sets info->hdr and info->len. */
2475 static int copy_module_from_user(const void __user *umod, unsigned long len,
2476                                   struct load_info *info)
2477 {
2478         int err;
2479 
2480         info->len = len;
2481         if (info->len < sizeof(*(info->hdr)))
2482                 return -ENOEXEC;
2483 
2484         err = security_kernel_module_from_file(NULL);
2485         if (err)
2486                 return err;
2487 
2488         /* Suck in entire file: we'll want most of it. */
2489         info->hdr = vmalloc(info->len);
2490         if (!info->hdr)
2491                 return -ENOMEM;
2492 
2493         if (copy_from_user(info->hdr, umod, info->len) != 0) {
2494                 vfree(info->hdr);
2495                 return -EFAULT;
2496         }
2497 
2498         return 0;
2499 }
2500 
2501 /* Sets info->hdr and info->len. */
2502 static int copy_module_from_fd(int fd, struct load_info *info)
2503 {
2504         struct fd f = fdget(fd);
2505         int err;
2506         struct kstat stat;
2507         loff_t pos;
2508         ssize_t bytes = 0;
2509 
2510         if (!f.file)
2511                 return -ENOEXEC;
2512 
2513         err = security_kernel_module_from_file(f.file);
2514         if (err)
2515                 goto out;
2516 
2517         err = vfs_getattr(&f.file->f_path, &stat);
2518         if (err)
2519                 goto out;
2520 
2521         if (stat.size > INT_MAX) {
2522                 err = -EFBIG;
2523                 goto out;
2524         }
2525 
2526         /* Don't hand 0 to vmalloc, it whines. */
2527         if (stat.size == 0) {
2528                 err = -EINVAL;
2529                 goto out;
2530         }
2531 
2532         info->hdr = vmalloc(stat.size);
2533         if (!info->hdr) {
2534                 err = -ENOMEM;
2535                 goto out;
2536         }
2537 
2538         pos = 0;
2539         while (pos < stat.size) {
2540                 bytes = kernel_read(f.file, pos, (char *)(info->hdr) + pos,
2541                                     stat.size - pos);
2542                 if (bytes < 0) {
2543                         vfree(info->hdr);
2544                         err = bytes;
2545                         goto out;
2546                 }
2547                 if (bytes == 0)
2548                         break;
2549                 pos += bytes;
2550         }
2551         info->len = pos;
2552 
2553 out:
2554         fdput(f);
2555         return err;
2556 }
2557 
2558 static void free_copy(struct load_info *info)
2559 {
2560         vfree(info->hdr);
2561 }
2562 
2563 static int rewrite_section_headers(struct load_info *info, int flags)
2564 {
2565         unsigned int i;
2566 
2567         /* This should always be true, but let's be sure. */
2568         info->sechdrs[0].sh_addr = 0;
2569 
2570         for (i = 1; i < info->hdr->e_shnum; i++) {
2571                 Elf_Shdr *shdr = &info->sechdrs[i];
2572                 if (shdr->sh_type != SHT_NOBITS
2573                     && info->len < shdr->sh_offset + shdr->sh_size) {
2574                         pr_err("Module len %lu truncated\n", info->len);
2575                         return -ENOEXEC;
2576                 }
2577 
2578                 /* Mark all sections sh_addr with their address in the
2579                    temporary image. */
2580                 shdr->sh_addr = (size_t)info->hdr + shdr->sh_offset;
2581 
2582 #ifndef CONFIG_MODULE_UNLOAD
2583                 /* Don't load .exit sections */
2584                 if (strstarts(info->secstrings+shdr->sh_name, ".exit"))
2585                         shdr->sh_flags &= ~(unsigned long)SHF_ALLOC;
2586 #endif
2587         }
2588 
2589         /* Track but don't keep modinfo and version sections. */
2590         if (flags & MODULE_INIT_IGNORE_MODVERSIONS)
2591                 info->index.vers = 0; /* Pretend no __versions section! */
2592         else
2593                 info->index.vers = find_sec(info, "__versions");
2594         info->index.info = find_sec(info, ".modinfo");
2595         info->sechdrs[info->index.info].sh_flags &= ~(unsigned long)SHF_ALLOC;
2596         info->sechdrs[info->index.vers].sh_flags &= ~(unsigned long)SHF_ALLOC;
2597         return 0;
2598 }
2599 
2600 /*
2601  * Set up our basic convenience variables (pointers to section headers,
2602  * search for module section index etc), and do some basic section
2603  * verification.
2604  *
2605  * Return the temporary module pointer (we'll replace it with the final
2606  * one when we move the module sections around).
2607  */
2608 static struct module *setup_load_info(struct load_info *info, int flags)
2609 {
2610         unsigned int i;
2611         int err;
2612         struct module *mod;
2613 
2614         /* Set up the convenience variables */
2615         info->sechdrs = (void *)info->hdr + info->hdr->e_shoff;
2616         info->secstrings = (void *)info->hdr
2617                 + info->sechdrs[info->hdr->e_shstrndx].sh_offset;
2618 
2619         err = rewrite_section_headers(info, flags);
2620         if (err)
2621                 return ERR_PTR(err);
2622 
2623         /* Find internal symbols and strings. */
2624         for (i = 1; i < info->hdr->e_shnum; i++) {
2625                 if (info->sechdrs[i].sh_type == SHT_SYMTAB) {
2626                         info->index.sym = i;
2627                         info->index.str = info->sechdrs[i].sh_link;
2628                         info->strtab = (char *)info->hdr
2629                                 + info->sechdrs[info->index.str].sh_offset;
2630                         break;
2631                 }
2632         }
2633 
2634         info->index.mod = find_sec(info, ".gnu.linkonce.this_module");
2635         if (!info->index.mod) {
2636                 pr_warn("No module found in object\n");
2637                 return ERR_PTR(-ENOEXEC);
2638         }
2639         /* This is temporary: point mod into copy of data. */
2640         mod = (void *)info->sechdrs[info->index.mod].sh_addr;
2641 
2642         if (info->index.sym == 0) {
2643                 pr_warn("%s: module has no symbols (stripped?)\n", mod->name);
2644                 return ERR_PTR(-ENOEXEC);
2645         }
2646 
2647         info->index.pcpu = find_pcpusec(info);
2648 
2649         /* Check module struct version now, before we try to use module. */
2650         if (!check_modstruct_version(info->sechdrs, info->index.vers, mod))
2651                 return ERR_PTR(-ENOEXEC);
2652 
2653         return mod;
2654 }
2655 
2656 static int check_modinfo(struct module *mod, struct load_info *info, int flags)
2657 {
2658         const char *modmagic = get_modinfo(info, "vermagic");
2659         int err;
2660 
2661         if (flags & MODULE_INIT_IGNORE_VERMAGIC)
2662                 modmagic = NULL;
2663 
2664         /* This is allowed: modprobe --force will invalidate it. */
2665         if (!modmagic) {
2666                 err = try_to_force_load(mod, "bad vermagic");
2667                 if (err)
2668                         return err;
2669         } else if (!same_magic(modmagic, vermagic, info->index.vers)) {
2670                 pr_err("%s: version magic '%s' should be '%s'\n",
2671                        mod->name, modmagic, vermagic);
2672                 return -ENOEXEC;
2673         }
2674 
2675         if (!get_modinfo(info, "intree"))
2676                 add_taint_module(mod, TAINT_OOT_MODULE, LOCKDEP_STILL_OK);
2677 
2678         if (get_modinfo(info, "staging")) {
2679                 add_taint_module(mod, TAINT_CRAP, LOCKDEP_STILL_OK);
2680                 pr_warn("%s: module is from the staging directory, the quality "
2681                         "is unknown, you have been warned.\n", mod->name);
2682         }
2683 
2684         /* Set up license info based on the info section */
2685         set_license(mod, get_modinfo(info, "license"));
2686 
2687         return 0;
2688 }
2689 
2690 static int find_module_sections(struct module *mod, struct load_info *info)
2691 {
2692         mod->kp = section_objs(info, "__param",
2693                                sizeof(*mod->kp), &mod->num_kp);
2694         mod->syms = section_objs(info, "__ksymtab",
2695                                  sizeof(*mod->syms), &mod->num_syms);
2696         mod->crcs = section_addr(info, "__kcrctab");
2697         mod->gpl_syms = section_objs(info, "__ksymtab_gpl",
2698                                      sizeof(*mod->gpl_syms),
2699                                      &mod->num_gpl_syms);
2700         mod->gpl_crcs = section_addr(info, "__kcrctab_gpl");
2701         mod->gpl_future_syms = section_objs(info,
2702                                             "__ksymtab_gpl_future",
2703                                             sizeof(*mod->gpl_future_syms),
2704                                             &mod->num_gpl_future_syms);
2705         mod->gpl_future_crcs = section_addr(info, "__kcrctab_gpl_future");
2706 
2707 #ifdef CONFIG_UNUSED_SYMBOLS
2708         mod->unused_syms = section_objs(info, "__ksymtab_unused",
2709                                         sizeof(*mod->unused_syms),
2710                                         &mod->num_unused_syms);
2711         mod->unused_crcs = section_addr(info, "__kcrctab_unused");
2712         mod->unused_gpl_syms = section_objs(info, "__ksymtab_unused_gpl",
2713                                             sizeof(*mod->unused_gpl_syms),
2714                                             &mod->num_unused_gpl_syms);
2715         mod->unused_gpl_crcs = section_addr(info, "__kcrctab_unused_gpl");
2716 #endif
2717 #ifdef CONFIG_CONSTRUCTORS
2718         mod->ctors = section_objs(info, ".ctors",
2719                                   sizeof(*mod->ctors), &mod->num_ctors);
2720         if (!mod->ctors)
2721                 mod->ctors = section_objs(info, ".init_array",
2722                                 sizeof(*mod->ctors), &mod->num_ctors);
2723         else if (find_sec(info, ".init_array")) {
2724                 /*
2725                  * This shouldn't happen with same compiler and binutils
2726                  * building all parts of the module.
2727                  */
2728                 pr_warn("%s: has both .ctors and .init_array.\n",
2729                        mod->name);
2730                 return -EINVAL;
2731         }
2732 #endif
2733 
2734 #ifdef CONFIG_TRACEPOINTS
2735         mod->tracepoints_ptrs = section_objs(info, "__tracepoints_ptrs",
2736                                              sizeof(*mod->tracepoints_ptrs),
2737                                              &mod->num_tracepoints);
2738 #endif
2739 #ifdef HAVE_JUMP_LABEL
2740         mod->jump_entries = section_objs(info, "__jump_table",
2741                                         sizeof(*mod->jump_entries),
2742                                         &mod->num_jump_entries);
2743 #endif
2744 #ifdef CONFIG_EVENT_TRACING
2745         mod->trace_events = section_objs(info, "_ftrace_events",
2746                                          sizeof(*mod->trace_events),
2747                                          &mod->num_trace_events);
2748 #endif
2749 #ifdef CONFIG_TRACING
2750         mod->trace_bprintk_fmt_start = section_objs(info, "__trace_printk_fmt",
2751                                          sizeof(*mod->trace_bprintk_fmt_start),
2752                                          &mod->num_trace_bprintk_fmt);
2753 #endif
2754 #ifdef CONFIG_FTRACE_MCOUNT_RECORD
2755         /* sechdrs[0].sh_size is always zero */
2756         mod->ftrace_callsites = section_objs(info, "__mcount_loc",
2757                                              sizeof(*mod->ftrace_callsites),
2758                                              &mod->num_ftrace_callsites);
2759 #endif
2760 
2761         mod->extable = section_objs(info, "__ex_table",
2762                                     sizeof(*mod->extable), &mod->num_exentries);
2763 
2764         if (section_addr(info, "__obsparm"))
2765                 pr_warn("%s: Ignoring obsolete parameters\n", mod->name);
2766 
2767         info->debug = section_objs(info, "__verbose",
2768                                    sizeof(*info->debug), &info->num_debug);
2769 
2770         return 0;
2771 }
2772 
2773 static int move_module(struct module *mod, struct load_info *info)
2774 {
2775         int i;
2776         void *ptr;
2777 
2778         /* Do the allocs. */
2779         ptr = module_alloc_update_bounds(mod->core_size);
2780         /*
2781          * The pointer to this block is stored in the module structure
2782          * which is inside the block. Just mark it as not being a
2783          * leak.
2784          */
2785         kmemleak_not_leak(ptr);
2786         if (!ptr)
2787                 return -ENOMEM;
2788 
2789         memset(ptr, 0, mod->core_size);
2790         mod->module_core = ptr;
2791 
2792         if (mod->init_size) {
2793                 ptr = module_alloc_update_bounds(mod->init_size);
2794                 /*
2795                  * The pointer to this block is stored in the module structure
2796                  * which is inside the block. This block doesn't need to be
2797                  * scanned as it contains data and code that will be freed
2798                  * after the module is initialized.
2799                  */
2800                 kmemleak_ignore(ptr);
2801                 if (!ptr) {
2802                         module_memfree(mod->module_core);
2803                         return -ENOMEM;
2804                 }
2805                 memset(ptr, 0, mod->init_size);
2806                 mod->module_init = ptr;
2807         } else
2808                 mod->module_init = NULL;
2809 
2810         /* Transfer each section which specifies SHF_ALLOC */
2811         pr_debug("final section addresses:\n");
2812         for (i = 0; i < info->hdr->e_shnum; i++) {
2813                 void *dest;
2814                 Elf_Shdr *shdr = &info->sechdrs[i];
2815 
2816                 if (!(shdr->sh_flags & SHF_ALLOC))
2817                         continue;
2818 
2819                 if (shdr->sh_entsize & INIT_OFFSET_MASK)
2820                         dest = mod->module_init
2821                                 + (shdr->sh_entsize & ~INIT_OFFSET_MASK);
2822                 else
2823                         dest = mod->module_core + shdr->sh_entsize;
2824 
2825                 if (shdr->sh_type != SHT_NOBITS)
2826                         memcpy(dest, (void *)shdr->sh_addr, shdr->sh_size);
2827                 /* Update sh_addr to point to copy in image. */
2828                 shdr->sh_addr = (unsigned long)dest;
2829                 pr_debug("\t0x%lx %s\n",
2830                          (long)shdr->sh_addr, info->secstrings + shdr->sh_name);
2831         }
2832 
2833         return 0;
2834 }
2835 
2836 static int check_module_license_and_versions(struct module *mod)
2837 {
2838         /*
2839          * ndiswrapper is under GPL by itself, but loads proprietary modules.
2840          * Don't use add_taint_module(), as it would prevent ndiswrapper from
2841          * using GPL-only symbols it needs.
2842          */
2843         if (strcmp(mod->name, "ndiswrapper") == 0)
2844                 add_taint(TAINT_PROPRIETARY_MODULE, LOCKDEP_NOW_UNRELIABLE);
2845 
2846         /* driverloader was caught wrongly pretending to be under GPL */
2847         if (strcmp(mod->name, "driverloader") == 0)
2848                 add_taint_module(mod, TAINT_PROPRIETARY_MODULE,
2849                                  LOCKDEP_NOW_UNRELIABLE);
2850 
2851         /* lve claims to be GPL but upstream won't provide source */
2852         if (strcmp(mod->name, "lve") == 0)
2853                 add_taint_module(mod, TAINT_PROPRIETARY_MODULE,
2854                                  LOCKDEP_NOW_UNRELIABLE);
2855 
2856 #ifdef CONFIG_MODVERSIONS
2857         if ((mod->num_syms && !mod->crcs)
2858             || (mod->num_gpl_syms && !mod->gpl_crcs)
2859             || (mod->num_gpl_future_syms && !mod->gpl_future_crcs)
2860 #ifdef CONFIG_UNUSED_SYMBOLS
2861             || (mod->num_unused_syms && !mod->unused_crcs)
2862             || (mod->num_unused_gpl_syms && !mod->unused_gpl_crcs)
2863 #endif
2864                 ) {
2865                 return try_to_force_load(mod,
2866                                          "no versions for exported symbols");
2867         }
2868 #endif
2869         return 0;
2870 }
2871 
2872 static void flush_module_icache(const struct module *mod)
2873 {
2874         mm_segment_t old_fs;
2875 
2876         /* flush the icache in correct context */
2877         old_fs = get_fs();
2878         set_fs(KERNEL_DS);
2879 
2880         /*
2881          * Flush the instruction cache, since we've played with text.
2882          * Do it before processing of module parameters, so the module
2883          * can provide parameter accessor functions of its own.
2884          */
2885         if (mod->module_init)
2886                 flush_icache_range((unsigned long)mod->module_init,
2887                                    (unsigned long)mod->module_init
2888                                    + mod->init_size);
2889         flush_icache_range((unsigned long)mod->module_core,
2890                            (unsigned long)mod->module_core + mod->core_size);
2891 
2892         set_fs(old_fs);
2893 }
2894 
2895 int __weak module_frob_arch_sections(Elf_Ehdr *hdr,
2896                                      Elf_Shdr *sechdrs,
2897                                      char *secstrings,
2898                                      struct module *mod)
2899 {
2900         return 0;
2901 }
2902 
2903 static struct module *layout_and_allocate(struct load_info *info, int flags)
2904 {
2905         /* Module within temporary copy. */
2906         struct module *mod;
2907         int err;
2908 
2909         mod = setup_load_info(info, flags);
2910         if (IS_ERR(mod))
2911                 return mod;
2912 
2913         err = check_modinfo(mod, info, flags);
2914         if (err)
2915                 return ERR_PTR(err);
2916 
2917         /* Allow arches to frob section contents and sizes.  */
2918         err = module_frob_arch_sections(info->hdr, info->sechdrs,
2919                                         info->secstrings, mod);
2920         if (err < 0)
2921                 return ERR_PTR(err);
2922 
2923         /* We will do a special allocation for per-cpu sections later. */
2924         info->sechdrs[info->index.pcpu].sh_flags &= ~(unsigned long)SHF_ALLOC;
2925 
2926         /* Determine total sizes, and put offsets in sh_entsize.  For now
2927            this is done generically; there doesn't appear to be any
2928            special cases for the architectures. */
2929         layout_sections(mod, info);
2930         layout_symtab(mod, info);
2931 
2932         /* Allocate and move to the final place */
2933         err = move_module(mod, info);
2934         if (err)
2935                 return ERR_PTR(err);
2936 
2937         /* Module has been copied to its final place now: return it. */
2938         mod = (void *)info->sechdrs[info->index.mod].sh_addr;
2939         kmemleak_load_module(mod, info);
2940         return mod;
2941 }
2942 
2943 /* mod is no longer valid after this! */
2944 static void module_deallocate(struct module *mod, struct load_info *info)
2945 {
2946         percpu_modfree(mod);
2947         module_arch_freeing_init(mod);
2948         module_memfree(mod->module_init);
2949         module_memfree(mod->module_core);
2950 }
2951 
2952 int __weak module_finalize(const Elf_Ehdr *hdr,
2953                            const Elf_Shdr *sechdrs,
2954                            struct module *me)
2955 {
2956         return 0;
2957 }
2958 
2959 static int post_relocation(struct module *mod, const struct load_info *info)
2960 {
2961         /* Sort exception table now relocations are done. */
2962         sort_extable(mod->extable, mod->extable + mod->num_exentries);
2963 
2964         /* Copy relocated percpu area over. */
2965         percpu_modcopy(mod, (void *)info->sechdrs[info->index.pcpu].sh_addr,
2966                        info->sechdrs[info->index.pcpu].sh_size);
2967 
2968         /* Setup kallsyms-specific fields. */
2969         add_kallsyms(mod, info);
2970 
2971         /* Arch-specific module finalizing. */
2972         return module_finalize(info->hdr, info->sechdrs, mod);
2973 }
2974 
2975 /* Is this module of this name done loading?  No locks held. */
2976 static bool finished_loading(const char *name)
2977 {
2978         struct module *mod;
2979         bool ret;
2980 
2981         mutex_lock(&module_mutex);
2982         mod = find_module_all(name, strlen(name), true);
2983         ret = !mod || mod->state == MODULE_STATE_LIVE
2984                 || mod->state == MODULE_STATE_GOING;
2985         mutex_unlock(&module_mutex);
2986 
2987         return ret;
2988 }
2989 
2990 /* Call module constructors. */
2991 static void do_mod_ctors(struct module *mod)
2992 {
2993 #ifdef CONFIG_CONSTRUCTORS
2994         unsigned long i;
2995 
2996         for (i = 0; i < mod->num_ctors; i++)
2997                 mod->ctors[i]();
2998 #endif
2999 }
3000 
3001 /* For freeing module_init on success, in case kallsyms traversing */
3002 struct mod_initfree {
3003         struct rcu_head rcu;
3004         void *module_init;
3005 };
3006 
3007 static void do_free_init(struct rcu_head *head)
3008 {
3009         struct mod_initfree *m = container_of(head, struct mod_initfree, rcu);
3010         module_memfree(m->module_init);
3011         kfree(m);
3012 }
3013 
3014 /* This is where the real work happens */
3015 static int do_init_module(struct module *mod)
3016 {
3017         int ret = 0;
3018         struct mod_initfree *freeinit;
3019 
3020         freeinit = kmalloc(sizeof(*freeinit), GFP_KERNEL);
3021         if (!freeinit) {
3022                 ret = -ENOMEM;
3023                 goto fail;
3024         }
3025         freeinit->module_init = mod->module_init;
3026 
3027         /*
3028          * We want to find out whether @mod uses async during init.  Clear
3029          * PF_USED_ASYNC.  async_schedule*() will set it.
3030          */
3031         current->flags &= ~PF_USED_ASYNC;
3032 
3033         do_mod_ctors(mod);
3034         /* Start the module */
3035         if (mod->init != NULL)
3036                 ret = do_one_initcall(mod->init);
3037         if (ret < 0) {
3038                 goto fail_free_freeinit;
3039         }
3040         if (ret > 0) {
3041                 pr_warn("%s: '%s'->init suspiciously returned %d, it should "
3042                         "follow 0/-E convention\n"
3043                         "%s: loading module anyway...\n",
3044                         __func__, mod->name, ret, __func__);
3045                 dump_stack();
3046         }
3047 
3048         /* Now it's a first class citizen! */
3049         mod->state = MODULE_STATE_LIVE;
3050         blocking_notifier_call_chain(&module_notify_list,
3051                                      MODULE_STATE_LIVE, mod);
3052 
3053         /*
3054          * We need to finish all async code before the module init sequence
3055          * is done.  This has potential to deadlock.  For example, a newly
3056          * detected block device can trigger request_module() of the
3057          * default iosched from async probing task.  Once userland helper
3058          * reaches here, async_synchronize_full() will wait on the async
3059          * task waiting on request_module() and deadlock.
3060          *
3061          * This deadlock is avoided by perfomring async_synchronize_full()
3062          * iff module init queued any async jobs.  This isn't a full
3063          * solution as it will deadlock the same if module loading from
3064          * async jobs nests more than once; however, due to the various
3065          * constraints, this hack seems to be the best option for now.
3066          * Please refer to the following thread for details.
3067          *
3068          * http://thread.gmane.org/gmane.linux.kernel/1420814
3069          */
3070         if (current->flags & PF_USED_ASYNC)
3071                 async_synchronize_full();
3072 
3073         mutex_lock(&module_mutex);
3074         /* Drop initial reference. */
3075         module_put(mod);
3076         trim_init_extable(mod);
3077 #ifdef CONFIG_KALLSYMS
3078         mod->num_symtab = mod->core_num_syms;
3079         mod->symtab = mod->core_symtab;
3080         mod->strtab = mod->core_strtab;
3081 #endif
3082         unset_module_init_ro_nx(mod);
3083         module_arch_freeing_init(mod);
3084         mod->module_init = NULL;
3085         mod->init_size = 0;
3086         mod->init_ro_size = 0;
3087         mod->init_text_size = 0;
3088         /*
3089          * We want to free module_init, but be aware that kallsyms may be
3090          * walking this with preempt disabled.  In all the failure paths,
3091          * we call synchronize_rcu/synchronize_sched, but we don't want
3092          * to slow down the success path, so use actual RCU here.
3093          */
3094         call_rcu(&freeinit->rcu, do_free_init);
3095         mutex_unlock(&module_mutex);
3096         wake_up_all(&module_wq);
3097 
3098         return 0;
3099 
3100 fail_free_freeinit:
3101         kfree(freeinit);
3102 fail:
3103         /* Try to protect us from buggy refcounters. */
3104         mod->state = MODULE_STATE_GOING;
3105         synchronize_sched();
3106         module_put(mod);
3107         blocking_notifier_call_chain(&module_notify_list,
3108                                      MODULE_STATE_GOING, mod);
3109         free_module(mod);
3110         wake_up_all(&module_wq);
3111         return ret;
3112 }
3113 
3114 static int may_init_module(void)
3115 {
3116         if (!capable(CAP_SYS_MODULE) || modules_disabled)
3117                 return -EPERM;
3118 
3119         return 0;
3120 }
3121 
3122 /*
3123  * Can't use wait_event_interruptible() because our condition
3124  * 'finished_loading()' contains a blocking primitive itself (mutex_lock).
3125  */
3126 static int wait_finished_loading(struct module *mod)
3127 {
3128         DEFINE_WAIT_FUNC(wait, woken_wake_function);
3129         int ret = 0;
3130 
3131         add_wait_queue(&module_wq, &wait);
3132         for (;;) {
3133                 if (finished_loading(mod->name))
3134                         break;
3135 
3136                 if (signal_pending(current)) {
3137                         ret = -ERESTARTSYS;
3138                         break;
3139                 }
3140 
3141                 wait_woken(&wait, TASK_INTERRUPTIBLE, MAX_SCHEDULE_TIMEOUT);
3142         }
3143         remove_wait_queue(&module_wq, &wait);
3144 
3145         return ret;
3146 }
3147 
3148 /*
3149  * We try to place it in the list now to make sure it's unique before
3150  * we dedicate too many resources.  In particular, temporary percpu
3151  * memory exhaustion.
3152  */
3153 static int add_unformed_module(struct module *mod)
3154 {
3155         int err;
3156         struct module *old;
3157 
3158         mod->state = MODULE_STATE_UNFORMED;
3159 
3160 again:
3161         mutex_lock(&module_mutex);
3162         old = find_module_all(mod->name, strlen(mod->name), true);
3163         if (old != NULL) {
3164                 if (old->state == MODULE_STATE_COMING
3165                     || old->state == MODULE_STATE_UNFORMED) {
3166                         /* Wait in case it fails to load. */
3167                         mutex_unlock(&module_mutex);
3168 
3169                         err = wait_finished_loading(mod);
3170                         if (err)
3171                                 goto out_unlocked;
3172                         goto again;
3173                 }
3174                 err = -EEXIST;
3175                 goto out;
3176         }
3177         list_add_rcu(&mod->list, &modules);
3178         err = 0;
3179 
3180 out:
3181         mutex_unlock(&module_mutex);
3182 out_unlocked:
3183         return err;
3184 }
3185 
3186 static int complete_formation(struct module *mod, struct load_info *info)
3187 {
3188         int err;
3189 
3190         mutex_lock(&module_mutex);
3191 
3192         /* Find duplicate symbols (must be called under lock). */
3193         err = verify_export_symbols(mod);
3194         if (err < 0)
3195                 goto out;
3196 
3197         /* This relies on module_mutex for list integrity. */
3198         module_bug_finalize(info->hdr, info->sechdrs, mod);
3199 
3200         /* Set RO and NX regions for core */
3201         set_section_ro_nx(mod->module_core,
3202                                 mod->core_text_size,
3203                                 mod->core_ro_size,
3204                                 mod->core_size);
3205 
3206         /* Set RO and NX regions for init */
3207         set_section_ro_nx(mod->module_init,
3208                                 mod->init_text_size,
3209                                 mod->init_ro_size,
3210                                 mod->init_size);
3211 
3212         /* Mark state as coming so strong_try_module_get() ignores us,
3213          * but kallsyms etc. can see us. */
3214         mod->state = MODULE_STATE_COMING;
3215         mutex_unlock(&module_mutex);
3216 
3217         blocking_notifier_call_chain(&module_notify_list,
3218                                      MODULE_STATE_COMING, mod);
3219         return 0;
3220 
3221 out:
3222         mutex_unlock(&module_mutex);
3223         return err;
3224 }
3225 
3226 static int unknown_module_param_cb(char *param, char *val, const char *modname)
3227 {
3228         /* Check for magic 'dyndbg' arg */
3229         int ret = ddebug_dyndbg_module_param_cb(param, val, modname);
3230         if (ret != 0)
3231                 pr_warn("%s: unknown parameter '%s' ignored\n", modname, param);
3232         return 0;
3233 }
3234 
3235 /* Allocate and load the module: note that size of section 0 is always
3236    zero, and we rely on this for optional sections. */
3237 static int load_module(struct load_info *info, const char __user *uargs,
3238                        int flags)
3239 {
3240         struct module *mod;
3241         long err;
3242         char *after_dashes;
3243 
3244         err = module_sig_check(info);
3245         if (err)
3246                 goto free_copy;
3247 
3248         err = elf_header_check(info);
3249         if (err)
3250                 goto free_copy;
3251 
3252         /* Figure out module layout, and allocate all the memory. */
3253         mod = layout_and_allocate(info, flags);
3254         if (IS_ERR(mod)) {
3255                 err = PTR_ERR(mod);
3256                 goto free_copy;
3257         }
3258 
3259         /* Reserve our place in the list. */
3260         err = add_unformed_module(mod);
3261         if (err)
3262                 goto free_module;
3263 
3264 #ifdef CONFIG_MODULE_SIG
3265         mod->sig_ok = info->sig_ok;
3266         if (!mod->sig_ok) {
3267                 pr_notice_once("%s: module verification failed: signature "
3268                                "and/or  required key missing - tainting "
3269                                "kernel\n", mod->name);
3270                 add_taint_module(mod, TAINT_UNSIGNED_MODULE, LOCKDEP_STILL_OK);
3271         }
3272 #endif
3273 
3274         /* To avoid stressing percpu allocator, do this once we're unique. */
3275         err = percpu_modalloc(mod, info);
3276         if (err)
3277                 goto unlink_mod;
3278 
3279         /* Now module is in final location, initialize linked lists, etc. */
3280         err = module_unload_init(mod);
3281         if (err)
3282                 goto unlink_mod;
3283 
3284         /* Now we've got everything in the final locations, we can
3285          * find optional sections. */
3286         err = find_module_sections(mod, info);
3287         if (err)
3288                 goto free_unload;
3289 
3290         err = check_module_license_and_versions(mod);
3291         if (err)
3292                 goto free_unload;
3293 
3294         /* Set up MODINFO_ATTR fields */
3295         setup_modinfo(mod, info);
3296 
3297         /* Fix up syms, so that st_value is a pointer to location. */
3298         err = simplify_symbols(mod, info);
3299         if (err < 0)
3300                 goto free_modinfo;
3301 
3302         err = apply_relocations(mod, info);
3303         if (err < 0)
3304                 goto free_modinfo;
3305 
3306         err = post_relocation(mod, info);
3307         if (err < 0)
3308                 goto free_modinfo;
3309 
3310         flush_module_icache(mod);
3311 
3312         /* Now copy in args */
3313         mod->args = strndup_user(uargs, ~0UL >> 1);
3314         if (IS_ERR(mod->args)) {
3315                 err = PTR_ERR(mod->args);
3316                 goto free_arch_cleanup;
3317         }
3318 
3319         dynamic_debug_setup(info->debug, info->num_debug);
3320 
3321         /* Ftrace init must be called in the MODULE_STATE_UNFORMED state */
3322         ftrace_module_init(mod);
3323 
3324         /* Finally it's fully formed, ready to start executing. */
3325         err = complete_formation(mod, info);
3326         if (err)
3327                 goto ddebug_cleanup;
3328 
3329         /* Module is ready to execute: parsing args may do that. */
3330         after_dashes = parse_args(mod->name, mod->args, mod->kp, mod->num_kp,
3331                                   -32768, 32767, unknown_module_param_cb);
3332         if (IS_ERR(after_dashes)) {
3333                 err = PTR_ERR(after_dashes);
3334                 goto bug_cleanup;
3335         } else if (after_dashes) {
3336                 pr_warn("%s: parameters '%s' after `--' ignored\n",
3337                        mod->name, after_dashes);
3338         }
3339 
3340         /* Link in to syfs. */
3341         err = mod_sysfs_setup(mod, info, mod->kp, mod->num_kp);
3342         if (err < 0)
3343                 goto bug_cleanup;
3344 
3345         /* Get rid of temporary copy. */
3346         free_copy(info);
3347 
3348         /* Done! */
3349         trace_module_load(mod);
3350 
3351         return do_init_module(mod);
3352 
3353  bug_cleanup:
3354         /* module_bug_cleanup needs module_mutex protection */
3355         mutex_lock(&module_mutex);
3356         module_bug_cleanup(mod);
3357         mutex_unlock(&module_mutex);
3358 
3359         /* we can't deallocate the module until we clear memory protection */
3360         unset_module_init_ro_nx(mod);
3361         unset_module_core_ro_nx(mod);
3362 
3363  ddebug_cleanup:
3364         dynamic_debug_remove(info->debug);
3365         synchronize_sched();
3366         kfree(mod->args);
3367  free_arch_cleanup:
3368         module_arch_cleanup(mod);
3369  free_modinfo:
3370         free_modinfo(mod);
3371  free_unload:
3372         module_unload_free(mod);
3373  unlink_mod:
3374         mutex_lock(&module_mutex);
3375         /* Unlink carefully: kallsyms could be walking list. */
3376         list_del_rcu(&mod->list);
3377         wake_up_all(&module_wq);
3378         /* Wait for RCU synchronizing before releasing mod->list. */
3379         synchronize_rcu();
3380         mutex_unlock(&module_mutex);
3381  free_module:
3382         module_deallocate(mod, info);
3383  free_copy:
3384         free_copy(info);
3385         return err;
3386 }
3387 
3388 SYSCALL_DEFINE3(init_module, void __user *, umod,
3389                 unsigned long, len, const char __user *, uargs)
3390 {
3391         int err;
3392         struct load_info info = { };
3393 
3394         err = may_init_module();
3395         if (err)
3396                 return err;
3397 
3398         pr_debug("init_module: umod=%p, len=%lu, uargs=%p\n",
3399                umod, len, uargs);
3400 
3401         err = copy_module_from_user(umod, len, &info);
3402         if (err)
3403                 return err;
3404 
3405         return load_module(&info, uargs, 0);
3406 }
3407 
3408 SYSCALL_DEFINE3(finit_module, int, fd, const char __user *, uargs, int, flags)
3409 {
3410         int err;
3411         struct load_info info = { };
3412 
3413         err = may_init_module();
3414         if (err)
3415                 return err;
3416 
3417         pr_debug("finit_module: fd=%d, uargs=%p, flags=%i\n", fd, uargs, flags);
3418 
3419         if (flags & ~(MODULE_INIT_IGNORE_MODVERSIONS
3420                       |MODULE_INIT_IGNORE_VERMAGIC))
3421                 return -EINVAL;
3422 
3423         err = copy_module_from_fd(fd, &info);
3424         if (err)
3425                 return err;
3426 
3427         return load_module(&info, uargs, flags);
3428 }
3429 
3430 static inline int within(unsigned long addr, void *start, unsigned long size)
3431 {
3432         return ((void *)addr >= start && (void *)addr < start + size);
3433 }
3434 
3435 #ifdef CONFIG_KALLSYMS
3436 /*
3437  * This ignores the intensely annoying "mapping symbols" found
3438  * in ARM ELF files: $a, $t and $d.
3439  */
3440 static inline int is_arm_mapping_symbol(const char *str)
3441 {
3442         if (str[0] == '.' && str[1] == 'L')
3443                 return true;
3444         return str[0] == '$' && strchr("axtd", str[1])
3445                && (str[2] == '\0' || str[2] == '.');
3446 }
3447 
3448 static const char *get_ksymbol(struct module *mod,
3449                                unsigned long addr,
3450                                unsigned long *size,
3451                                unsigned long *offset)
3452 {
3453         unsigned int i, best = 0;
3454         unsigned long nextval;
3455 
3456         /* At worse, next value is at end of module */
3457         if (within_module_init(addr, mod))
3458                 nextval = (unsigned long)mod->module_init+mod->init_text_size;
3459         else
3460                 nextval = (unsigned long)mod->module_core+mod->core_text_size;
3461 
3462         /* Scan for closest preceding symbol, and next symbol. (ELF
3463            starts real symbols at 1). */
3464         for (i = 1; i < mod->num_symtab; i++) {
3465                 if (mod->symtab[i].st_shndx == SHN_UNDEF)
3466                         continue;
3467 
3468                 /* We ignore unnamed symbols: they're uninformative
3469                  * and inserted at a whim. */
3470                 if (mod->symtab[i].st_value <= addr
3471                     && mod->symtab[i].st_value > mod->symtab[best].st_value
3472                     && *(mod->strtab + mod->symtab[i].st_name) != '\0'
3473                     && !is_arm_mapping_symbol(mod->strtab + mod->symtab[i].st_name))
3474                         best = i;
3475                 if (mod->symtab[i].st_value > addr
3476                     && mod->symtab[i].st_value < nextval
3477                     && *(mod->strtab + mod->symtab[i].st_name) != '\0'
3478                     && !is_arm_mapping_symbol(mod->strtab + mod->symtab[i].st_name))
3479                         nextval = mod->symtab[i].st_value;
3480         }
3481 
3482         if (!best)
3483                 return NULL;
3484 
3485         if (size)
3486                 *size = nextval - mod->symtab[best].st_value;
3487         if (offset)
3488                 *offset = addr - mod->symtab[best].st_value;
3489         return mod->strtab + mod->symtab[best].st_name;
3490 }
3491 
3492 /* For kallsyms to ask for address resolution.  NULL means not found.  Careful
3493  * not to lock to avoid deadlock on oopses, simply disable preemption. */
3494 const char *module_address_lookup(unsigned long addr,
3495                             unsigned long *size,
3496                             unsigned long *offset,
3497                             char **modname,
3498                             char *namebuf)
3499 {
3500         struct module *mod;
3501         const char *ret = NULL;
3502 
3503         preempt_disable();
3504         list_for_each_entry_rcu(mod, &modules, list) {
3505                 if (mod->state == MODULE_STATE_UNFORMED)
3506                         continue;
3507                 if (within_module(addr, mod)) {
3508                         if (modname)
3509                                 *modname = mod->name;
3510                         ret = get_ksymbol(mod, addr, size, offset);
3511                         break;
3512                 }
3513         }
3514         /* Make a copy in here where it's safe */
3515         if (ret) {
3516                 strncpy(namebuf, ret, KSYM_NAME_LEN - 1);
3517                 ret = namebuf;
3518         }
3519         preempt_enable();
3520         return ret;
3521 }
3522 
3523 int lookup_module_symbol_name(unsigned long addr, char *symname)
3524 {
3525         struct module *mod;
3526 
3527         preempt_disable();
3528         list_for_each_entry_rcu(mod, &modules, list) {
3529                 if (mod->state == MODULE_STATE_UNFORMED)
3530                         continue;
3531                 if (within_module(addr, mod)) {
3532                         const char *sym;
3533 
3534                         sym = get_ksymbol(mod, addr, NULL, NULL);
3535                         if (!sym)
3536                                 goto out;
3537                         strlcpy(symname, sym, KSYM_NAME_LEN);
3538                         preempt_enable();
3539                         return 0;
3540                 }
3541         }
3542 out:
3543         preempt_enable();
3544         return -ERANGE;
3545 }
3546 
3547 int lookup_module_symbol_attrs(unsigned long addr, unsigned long *size,
3548                         unsigned long *offset, char *modname, char *name)
3549 {
3550         struct module *mod;
3551 
3552         preempt_disable();
3553         list_for_each_entry_rcu(mod, &modules, list) {
3554                 if (mod->state == MODULE_STATE_UNFORMED)
3555                         continue;
3556                 if (within_module(addr, mod)) {
3557                         const char *sym;
3558 
3559                         sym = get_ksymbol(mod, addr, size, offset);
3560                         if (!sym)
3561                                 goto out;
3562                         if (modname)
3563                                 strlcpy(modname, mod->name, MODULE_NAME_LEN);
3564                         if (name)
3565                                 strlcpy(name, sym, KSYM_NAME_LEN);
3566                         preempt_enable();
3567                         return 0;
3568                 }
3569         }
3570 out:
3571         preempt_enable();
3572         return -ERANGE;
3573 }
3574 
3575 int module_get_kallsym(unsigned int symnum, unsigned long *value, char *type,
3576                         char *name, char *module_name, int *exported)
3577 {
3578         struct module *mod;
3579 
3580         preempt_disable();
3581         list_for_each_entry_rcu(mod, &modules, list) {
3582                 if (mod->state == MODULE_STATE_UNFORMED)
3583                         continue;
3584                 if (symnum < mod->num_symtab) {
3585                         *value = mod->symtab[symnum].st_value;
3586                         *type = mod->symtab[symnum].st_info;
3587                         strlcpy(name, mod->strtab + mod->symtab[symnum].st_name,
3588                                 KSYM_NAME_LEN);
3589                         strlcpy(module_name, mod->name, MODULE_NAME_LEN);
3590                         *exported = is_exported(name, *value, mod);
3591                         preempt_enable();
3592                         return 0;
3593                 }
3594                 symnum -= mod->num_symtab;
3595         }
3596         preempt_enable();
3597         return -ERANGE;
3598 }
3599 
3600 static unsigned long mod_find_symname(struct module *mod, const char *name)
3601 {
3602         unsigned int i;
3603 
3604         for (i = 0; i < mod->num_symtab; i++)
3605                 if (strcmp(name, mod->strtab+mod->symtab[i].st_name) == 0 &&
3606                     mod->symtab[i].st_info != 'U')
3607                         return mod->symtab[i].st_value;
3608         return 0;
3609 }
3610 
3611 /* Look for this name: can be of form module:name. */
3612 unsigned long module_kallsyms_lookup_name(const char *name)
3613 {
3614         struct module *mod;
3615         char *colon;
3616         unsigned long ret = 0;
3617 
3618         /* Don't lock: we're in enough trouble already. */
3619         preempt_disable();
3620         if ((colon = strchr(name, ':')) != NULL) {
3621                 if ((mod = find_module_all(name, colon - name, false)) != NULL)
3622                         ret = mod_find_symname(mod, colon+1);
3623         } else {
3624                 list_for_each_entry_rcu(mod, &modules, list) {
3625                         if (mod->state == MODULE_STATE_UNFORMED)
3626                                 continue;
3627                         if ((ret = mod_find_symname(mod, name)) != 0)
3628                                 break;
3629                 }
3630         }
3631         preempt_enable();
3632         return ret;
3633 }
3634 
3635 int module_kallsyms_on_each_symbol(int (*fn)(void *, const char *,
3636                                              struct module *, unsigned long),
3637                                    void *data)
3638 {
3639         struct module *mod;
3640         unsigned int i;
3641         int ret;
3642 
3643         list_for_each_entry(mod, &modules, list) {
3644                 if (mod->state == MODULE_STATE_UNFORMED)
3645                         continue;
3646                 for (i = 0; i < mod->num_symtab; i++) {
3647                         ret = fn(data, mod->strtab + mod->symtab[i].st_name,
3648                                  mod, mod->symtab[i].st_value);
3649                         if (ret != 0)
3650                                 return ret;
3651                 }
3652         }
3653         return 0;
3654 }
3655 #endif /* CONFIG_KALLSYMS */
3656 
3657 static char *module_flags(struct module *mod, char *buf)
3658 {
3659         int bx = 0;
3660 
3661         BUG_ON(mod->state == MODULE_STATE_UNFORMED);
3662         if (mod->taints ||
3663             mod->state == MODULE_STATE_GOING ||
3664             mod->state == MODULE_STATE_COMING) {
3665                 buf[bx++] = '(';
3666                 bx += module_flags_taint(mod, buf + bx);
3667                 /* Show a - for module-is-being-unloaded */
3668                 if (mod->state == MODULE_STATE_GOING)
3669                         buf[bx++] = '-';
3670                 /* Show a + for module-is-being-loaded */
3671                 if (mod->state == MODULE_STATE_COMING)
3672                         buf[bx++] = '+';
3673                 buf[bx++] = ')';
3674         }
3675         buf[bx] = '\0';
3676 
3677         return buf;
3678 }
3679 
3680 #ifdef CONFIG_PROC_FS
3681 /* Called by the /proc file system to return a list of modules. */
3682 static void *m_start(struct seq_file *m, loff_t *pos)
3683 {
3684         mutex_lock(&module_mutex);
3685         return seq_list_start(&modules, *pos);
3686 }
3687 
3688 static void *m_next(struct seq_file *m, void *p, loff_t *pos)
3689 {
3690         return seq_list_next(p, &modules, pos);
3691 }
3692 
3693 static void m_stop(struct seq_file *m, void *p)
3694 {
3695         mutex_unlock(&module_mutex);
3696 }
3697 
3698 static int m_show(struct seq_file *m, void *p)
3699 {
3700         struct module *mod = list_entry(p, struct module, list);
3701         char buf[8];
3702 
3703         /* We always ignore unformed modules. */
3704         if (mod->state == MODULE_STATE_UNFORMED)
3705                 return 0;
3706 
3707         seq_printf(m, "%s %u",
3708                    mod->name, mod->init_size + mod->core_size);
3709         print_unload_info(m, mod);
3710 
3711         /* Informative for users. */
3712         seq_printf(m, " %s",
3713                    mod->state == MODULE_STATE_GOING ? "Unloading" :
3714                    mod->state == MODULE_STATE_COMING ? "Loading" :
3715                    "Live");
3716         /* Used by oprofile and other similar tools. */
3717         seq_printf(m, " 0x%pK", mod->module_core);
3718 
3719         /* Taints info */
3720         if (mod->taints)
3721                 seq_printf(m, " %s", module_flags(mod, buf));
3722 
3723         seq_puts(m, "\n");
3724         return 0;
3725 }
3726 
3727 /* Format: modulename size refcount deps address
3728 
3729    Where refcount is a number or -, and deps is a comma-separated list
3730    of depends or -.
3731 */
3732 static const struct seq_operations modules_op = {
3733         .start  = m_start,
3734         .next   = m_next,
3735         .stop   = m_stop,
3736         .show   = m_show
3737 };
3738 
3739 static int modules_open(struct inode *inode, struct file *file)
3740 {
3741         return seq_open(file, &modules_op);
3742 }
3743 
3744 static const struct file_operations proc_modules_operations = {
3745         .open           = modules_open,
3746         .read           = seq_read,
3747         .llseek         = seq_lseek,
3748         .release        = seq_release,
3749 };
3750 
3751 static int __init proc_modules_init(void)
3752 {
3753         proc_create("modules", 0, NULL, &proc_modules_operations);
3754         return 0;
3755 }
3756 module_init(proc_modules_init);
3757 #endif
3758 
3759 /* Given an address, look for it in the module exception tables. */
3760 const struct exception_table_entry *search_module_extables(unsigned long addr)
3761 {
3762         const struct exception_table_entry *e = NULL;
3763         struct module *mod;
3764 
3765         preempt_disable();
3766         list_for_each_entry_rcu(mod, &modules, list) {
3767                 if (mod->state == MODULE_STATE_UNFORMED)
3768                         continue;
3769                 if (mod->num_exentries == 0)
3770                         continue;
3771 
3772                 e = search_extable(mod->extable,
3773                                    mod->extable + mod->num_exentries - 1,
3774                                    addr);
3775                 if (e)
3776                         break;
3777         }
3778         preempt_enable();
3779 
3780         /* Now, if we found one, we are running inside it now, hence
3781            we cannot unload the module, hence no refcnt needed. */
3782         return e;
3783 }
3784 
3785 /*
3786  * is_module_address - is this address inside a module?
3787  * @addr: the address to check.
3788  *
3789  * See is_module_text_address() if you simply want to see if the address
3790  * is code (not data).
3791  */
3792 bool is_module_address(unsigned long addr)
3793 {
3794         bool ret;
3795 
3796         preempt_disable();
3797         ret = __module_address(addr) != NULL;
3798         preempt_enable();
3799 
3800         return ret;
3801 }
3802 
3803 /*
3804  * __module_address - get the module which contains an address.
3805  * @addr: the address.
3806  *
3807  * Must be called with preempt disabled or module mutex held so that
3808  * module doesn't get freed during this.
3809  */
3810 struct module *__module_address(unsigned long addr)
3811 {
3812         struct module *mod;
3813 
3814         if (addr < module_addr_min || addr > module_addr_max)
3815                 return NULL;
3816 
3817         list_for_each_entry_rcu(mod, &modules, list) {
3818                 if (mod->state == MODULE_STATE_UNFORMED)
3819                         continue;
3820                 if (within_module(addr, mod))
3821                         return mod;
3822         }
3823         return NULL;
3824 }
3825 EXPORT_SYMBOL_GPL(__module_address);
3826 
3827 /*
3828  * is_module_text_address - is this address inside module code?
3829  * @addr: the address to check.
3830  *
3831  * See is_module_address() if you simply want to see if the address is
3832  * anywhere in a module.  See kernel_text_address() for testing if an
3833  * address corresponds to kernel or module code.
3834  */
3835 bool is_module_text_address(unsigned long addr)
3836 {
3837         bool ret;
3838 
3839         preempt_disable();
3840         ret = __module_text_address(addr) != NULL;
3841         preempt_enable();
3842 
3843         return ret;
3844 }
3845 
3846 /*
3847  * __module_text_address - get the module whose code contains an address.
3848  * @addr: the address.
3849  *
3850  * Must be called with preempt disabled or module mutex held so that
3851  * module doesn't get freed during this.
3852  */
3853 struct module *__module_text_address(unsigned long addr)
3854 {
3855         struct module *mod = __module_address(addr);
3856         if (mod) {
3857                 /* Make sure it's within the text section. */
3858                 if (!within(addr, mod->module_init, mod->init_text_size)
3859                     && !within(addr, mod->module_core, mod->core_text_size))
3860                         mod = NULL;
3861         }
3862         return mod;
3863 }
3864 EXPORT_SYMBOL_GPL(__module_text_address);
3865 
3866 /* Don't grab lock, we're oopsing. */
3867 void print_modules(void)
3868 {
3869         struct module *mod;
3870         char buf[8];
3871 
3872         printk(KERN_DEFAULT "Modules linked in:");
3873         /* Most callers should already have preempt disabled, but make sure */
3874         preempt_disable();
3875         list_for_each_entry_rcu(mod, &modules, list) {
3876                 if (mod->state == MODULE_STATE_UNFORMED)
3877                         continue;
3878                 pr_cont(" %s%s", mod->name, module_flags(mod, buf));
3879         }
3880         preempt_enable();
3881         if (last_unloaded_module[0])
3882                 pr_cont(" [last unloaded: %s]", last_unloaded_module);
3883         pr_cont("\n");
3884 }
3885 
3886 #ifdef CONFIG_MODVERSIONS
3887 /* Generate the signature for all relevant module structures here.
3888  * If these change, we don't want to try to parse the module. */
3889 void module_layout(struct module *mod,
3890                    struct modversion_info *ver,
3891                    struct kernel_param *kp,
3892                    struct kernel_symbol *ks,
3893                    struct tracepoint * const *tp)
3894 {
3895 }
3896 EXPORT_SYMBOL(module_layout);
3897 #endif
3898 

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