USB: EHCI: fix compiler warning introduced by commit 2a40f324541e
[linux/fpc-iii.git] / kernel / module.c
blob8358f4697c0c3aea77aba802833660d4082b7c13
1 /*
2 Copyright (C) 2002 Richard Henderson
3 Copyright (C) 2001 Rusty Russell, 2002, 2010 Rusty Russell IBM.
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.
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.
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
19 #include <linux/export.h>
20 #include <linux/moduleloader.h>
21 #include <linux/trace_events.h>
22 #include <linux/init.h>
23 #include <linux/kallsyms.h>
24 #include <linux/file.h>
25 #include <linux/fs.h>
26 #include <linux/sysfs.h>
27 #include <linux/kernel.h>
28 #include <linux/slab.h>
29 #include <linux/vmalloc.h>
30 #include <linux/elf.h>
31 #include <linux/proc_fs.h>
32 #include <linux/security.h>
33 #include <linux/seq_file.h>
34 #include <linux/syscalls.h>
35 #include <linux/fcntl.h>
36 #include <linux/rcupdate.h>
37 #include <linux/capability.h>
38 #include <linux/cpu.h>
39 #include <linux/moduleparam.h>
40 #include <linux/errno.h>
41 #include <linux/err.h>
42 #include <linux/vermagic.h>
43 #include <linux/notifier.h>
44 #include <linux/sched.h>
45 #include <linux/device.h>
46 #include <linux/string.h>
47 #include <linux/mutex.h>
48 #include <linux/rculist.h>
49 #include <asm/uaccess.h>
50 #include <asm/cacheflush.h>
51 #include <asm/mmu_context.h>
52 #include <linux/license.h>
53 #include <asm/sections.h>
54 #include <linux/tracepoint.h>
55 #include <linux/ftrace.h>
56 #include <linux/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"
65 #define CREATE_TRACE_POINTS
66 #include <trace/events/module.h>
68 #ifndef ARCH_SHF_SMALL
69 #define ARCH_SHF_SMALL 0
70 #endif
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
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
83 /* If this is set, the section belongs in the init part of the module */
84 #define INIT_OFFSET_MASK (1UL << (BITS_PER_LONG-1))
87 * Mutex protects:
88 * 1) List of modules (also safely readable with preempt_disable),
89 * 2) module_use links,
90 * 3) module_addr_min/module_addr_max.
91 * (delete and add uses RCU list operations). */
92 DEFINE_MUTEX(module_mutex);
93 EXPORT_SYMBOL_GPL(module_mutex);
94 static LIST_HEAD(modules);
96 #ifdef CONFIG_MODULES_TREE_LOOKUP
99 * Use a latched RB-tree for __module_address(); this allows us to use
100 * RCU-sched lookups of the address from any context.
102 * This is conditional on PERF_EVENTS || TRACING because those can really hit
103 * __module_address() hard by doing a lot of stack unwinding; potentially from
104 * NMI context.
107 static __always_inline unsigned long __mod_tree_val(struct latch_tree_node *n)
109 struct module_layout *layout = container_of(n, struct module_layout, mtn.node);
111 return (unsigned long)layout->base;
114 static __always_inline unsigned long __mod_tree_size(struct latch_tree_node *n)
116 struct module_layout *layout = container_of(n, struct module_layout, mtn.node);
118 return (unsigned long)layout->size;
121 static __always_inline bool
122 mod_tree_less(struct latch_tree_node *a, struct latch_tree_node *b)
124 return __mod_tree_val(a) < __mod_tree_val(b);
127 static __always_inline int
128 mod_tree_comp(void *key, struct latch_tree_node *n)
130 unsigned long val = (unsigned long)key;
131 unsigned long start, end;
133 start = __mod_tree_val(n);
134 if (val < start)
135 return -1;
137 end = start + __mod_tree_size(n);
138 if (val >= end)
139 return 1;
141 return 0;
144 static const struct latch_tree_ops mod_tree_ops = {
145 .less = mod_tree_less,
146 .comp = mod_tree_comp,
149 static struct mod_tree_root {
150 struct latch_tree_root root;
151 unsigned long addr_min;
152 unsigned long addr_max;
153 } mod_tree __cacheline_aligned = {
154 .addr_min = -1UL,
157 #define module_addr_min mod_tree.addr_min
158 #define module_addr_max mod_tree.addr_max
160 static noinline void __mod_tree_insert(struct mod_tree_node *node)
162 latch_tree_insert(&node->node, &mod_tree.root, &mod_tree_ops);
165 static void __mod_tree_remove(struct mod_tree_node *node)
167 latch_tree_erase(&node->node, &mod_tree.root, &mod_tree_ops);
171 * These modifications: insert, remove_init and remove; are serialized by the
172 * module_mutex.
174 static void mod_tree_insert(struct module *mod)
176 mod->core_layout.mtn.mod = mod;
177 mod->init_layout.mtn.mod = mod;
179 __mod_tree_insert(&mod->core_layout.mtn);
180 if (mod->init_layout.size)
181 __mod_tree_insert(&mod->init_layout.mtn);
184 static void mod_tree_remove_init(struct module *mod)
186 if (mod->init_layout.size)
187 __mod_tree_remove(&mod->init_layout.mtn);
190 static void mod_tree_remove(struct module *mod)
192 __mod_tree_remove(&mod->core_layout.mtn);
193 mod_tree_remove_init(mod);
196 static struct module *mod_find(unsigned long addr)
198 struct latch_tree_node *ltn;
200 ltn = latch_tree_find((void *)addr, &mod_tree.root, &mod_tree_ops);
201 if (!ltn)
202 return NULL;
204 return container_of(ltn, struct mod_tree_node, node)->mod;
207 #else /* MODULES_TREE_LOOKUP */
209 static unsigned long module_addr_min = -1UL, module_addr_max = 0;
211 static void mod_tree_insert(struct module *mod) { }
212 static void mod_tree_remove_init(struct module *mod) { }
213 static void mod_tree_remove(struct module *mod) { }
215 static struct module *mod_find(unsigned long addr)
217 struct module *mod;
219 list_for_each_entry_rcu(mod, &modules, list) {
220 if (within_module(addr, mod))
221 return mod;
224 return NULL;
227 #endif /* MODULES_TREE_LOOKUP */
230 * Bounds of module text, for speeding up __module_address.
231 * Protected by module_mutex.
233 static void __mod_update_bounds(void *base, unsigned int size)
235 unsigned long min = (unsigned long)base;
236 unsigned long max = min + size;
238 if (min < module_addr_min)
239 module_addr_min = min;
240 if (max > module_addr_max)
241 module_addr_max = max;
244 static void mod_update_bounds(struct module *mod)
246 __mod_update_bounds(mod->core_layout.base, mod->core_layout.size);
247 if (mod->init_layout.size)
248 __mod_update_bounds(mod->init_layout.base, mod->init_layout.size);
251 #ifdef CONFIG_KGDB_KDB
252 struct list_head *kdb_modules = &modules; /* kdb needs the list of modules */
253 #endif /* CONFIG_KGDB_KDB */
255 static void module_assert_mutex(void)
257 lockdep_assert_held(&module_mutex);
260 static void module_assert_mutex_or_preempt(void)
262 #ifdef CONFIG_LOCKDEP
263 if (unlikely(!debug_locks))
264 return;
266 WARN_ON(!rcu_read_lock_sched_held() &&
267 !lockdep_is_held(&module_mutex));
268 #endif
271 static bool sig_enforce = IS_ENABLED(CONFIG_MODULE_SIG_FORCE);
272 #ifndef CONFIG_MODULE_SIG_FORCE
273 module_param(sig_enforce, bool_enable_only, 0644);
274 #endif /* !CONFIG_MODULE_SIG_FORCE */
276 /* Block module loading/unloading? */
277 int modules_disabled = 0;
278 core_param(nomodule, modules_disabled, bint, 0);
280 /* Waiting for a module to finish initializing? */
281 static DECLARE_WAIT_QUEUE_HEAD(module_wq);
283 static BLOCKING_NOTIFIER_HEAD(module_notify_list);
285 int register_module_notifier(struct notifier_block *nb)
287 return blocking_notifier_chain_register(&module_notify_list, nb);
289 EXPORT_SYMBOL(register_module_notifier);
291 int unregister_module_notifier(struct notifier_block *nb)
293 return blocking_notifier_chain_unregister(&module_notify_list, nb);
295 EXPORT_SYMBOL(unregister_module_notifier);
297 struct load_info {
298 Elf_Ehdr *hdr;
299 unsigned long len;
300 Elf_Shdr *sechdrs;
301 char *secstrings, *strtab;
302 unsigned long symoffs, stroffs;
303 struct _ddebug *debug;
304 unsigned int num_debug;
305 bool sig_ok;
306 struct {
307 unsigned int sym, str, mod, vers, info, pcpu;
308 } index;
311 /* We require a truly strong try_module_get(): 0 means failure due to
312 ongoing or failed initialization etc. */
313 static inline int strong_try_module_get(struct module *mod)
315 BUG_ON(mod && mod->state == MODULE_STATE_UNFORMED);
316 if (mod && mod->state == MODULE_STATE_COMING)
317 return -EBUSY;
318 if (try_module_get(mod))
319 return 0;
320 else
321 return -ENOENT;
324 static inline void add_taint_module(struct module *mod, unsigned flag,
325 enum lockdep_ok lockdep_ok)
327 add_taint(flag, lockdep_ok);
328 mod->taints |= (1U << flag);
332 * A thread that wants to hold a reference to a module only while it
333 * is running can call this to safely exit. nfsd and lockd use this.
335 void __module_put_and_exit(struct module *mod, long code)
337 module_put(mod);
338 do_exit(code);
340 EXPORT_SYMBOL(__module_put_and_exit);
342 /* Find a module section: 0 means not found. */
343 static unsigned int find_sec(const struct load_info *info, const char *name)
345 unsigned int i;
347 for (i = 1; i < info->hdr->e_shnum; i++) {
348 Elf_Shdr *shdr = &info->sechdrs[i];
349 /* Alloc bit cleared means "ignore it." */
350 if ((shdr->sh_flags & SHF_ALLOC)
351 && strcmp(info->secstrings + shdr->sh_name, name) == 0)
352 return i;
354 return 0;
357 /* Find a module section, or NULL. */
358 static void *section_addr(const struct load_info *info, const char *name)
360 /* Section 0 has sh_addr 0. */
361 return (void *)info->sechdrs[find_sec(info, name)].sh_addr;
364 /* Find a module section, or NULL. Fill in number of "objects" in section. */
365 static void *section_objs(const struct load_info *info,
366 const char *name,
367 size_t object_size,
368 unsigned int *num)
370 unsigned int sec = find_sec(info, name);
372 /* Section 0 has sh_addr 0 and sh_size 0. */
373 *num = info->sechdrs[sec].sh_size / object_size;
374 return (void *)info->sechdrs[sec].sh_addr;
377 /* Provided by the linker */
378 extern const struct kernel_symbol __start___ksymtab[];
379 extern const struct kernel_symbol __stop___ksymtab[];
380 extern const struct kernel_symbol __start___ksymtab_gpl[];
381 extern const struct kernel_symbol __stop___ksymtab_gpl[];
382 extern const struct kernel_symbol __start___ksymtab_gpl_future[];
383 extern const struct kernel_symbol __stop___ksymtab_gpl_future[];
384 extern const unsigned long __start___kcrctab[];
385 extern const unsigned long __start___kcrctab_gpl[];
386 extern const unsigned long __start___kcrctab_gpl_future[];
387 #ifdef CONFIG_UNUSED_SYMBOLS
388 extern const struct kernel_symbol __start___ksymtab_unused[];
389 extern const struct kernel_symbol __stop___ksymtab_unused[];
390 extern const struct kernel_symbol __start___ksymtab_unused_gpl[];
391 extern const struct kernel_symbol __stop___ksymtab_unused_gpl[];
392 extern const unsigned long __start___kcrctab_unused[];
393 extern const unsigned long __start___kcrctab_unused_gpl[];
394 #endif
396 #ifndef CONFIG_MODVERSIONS
397 #define symversion(base, idx) NULL
398 #else
399 #define symversion(base, idx) ((base != NULL) ? ((base) + (idx)) : NULL)
400 #endif
402 static bool each_symbol_in_section(const struct symsearch *arr,
403 unsigned int arrsize,
404 struct module *owner,
405 bool (*fn)(const struct symsearch *syms,
406 struct module *owner,
407 void *data),
408 void *data)
410 unsigned int j;
412 for (j = 0; j < arrsize; j++) {
413 if (fn(&arr[j], owner, data))
414 return true;
417 return false;
420 /* Returns true as soon as fn returns true, otherwise false. */
421 bool each_symbol_section(bool (*fn)(const struct symsearch *arr,
422 struct module *owner,
423 void *data),
424 void *data)
426 struct module *mod;
427 static const struct symsearch arr[] = {
428 { __start___ksymtab, __stop___ksymtab, __start___kcrctab,
429 NOT_GPL_ONLY, false },
430 { __start___ksymtab_gpl, __stop___ksymtab_gpl,
431 __start___kcrctab_gpl,
432 GPL_ONLY, false },
433 { __start___ksymtab_gpl_future, __stop___ksymtab_gpl_future,
434 __start___kcrctab_gpl_future,
435 WILL_BE_GPL_ONLY, false },
436 #ifdef CONFIG_UNUSED_SYMBOLS
437 { __start___ksymtab_unused, __stop___ksymtab_unused,
438 __start___kcrctab_unused,
439 NOT_GPL_ONLY, true },
440 { __start___ksymtab_unused_gpl, __stop___ksymtab_unused_gpl,
441 __start___kcrctab_unused_gpl,
442 GPL_ONLY, true },
443 #endif
446 module_assert_mutex_or_preempt();
448 if (each_symbol_in_section(arr, ARRAY_SIZE(arr), NULL, fn, data))
449 return true;
451 list_for_each_entry_rcu(mod, &modules, list) {
452 struct symsearch arr[] = {
453 { mod->syms, mod->syms + mod->num_syms, mod->crcs,
454 NOT_GPL_ONLY, false },
455 { mod->gpl_syms, mod->gpl_syms + mod->num_gpl_syms,
456 mod->gpl_crcs,
457 GPL_ONLY, false },
458 { mod->gpl_future_syms,
459 mod->gpl_future_syms + mod->num_gpl_future_syms,
460 mod->gpl_future_crcs,
461 WILL_BE_GPL_ONLY, false },
462 #ifdef CONFIG_UNUSED_SYMBOLS
463 { mod->unused_syms,
464 mod->unused_syms + mod->num_unused_syms,
465 mod->unused_crcs,
466 NOT_GPL_ONLY, true },
467 { mod->unused_gpl_syms,
468 mod->unused_gpl_syms + mod->num_unused_gpl_syms,
469 mod->unused_gpl_crcs,
470 GPL_ONLY, true },
471 #endif
474 if (mod->state == MODULE_STATE_UNFORMED)
475 continue;
477 if (each_symbol_in_section(arr, ARRAY_SIZE(arr), mod, fn, data))
478 return true;
480 return false;
482 EXPORT_SYMBOL_GPL(each_symbol_section);
484 struct find_symbol_arg {
485 /* Input */
486 const char *name;
487 bool gplok;
488 bool warn;
490 /* Output */
491 struct module *owner;
492 const unsigned long *crc;
493 const struct kernel_symbol *sym;
496 static bool check_symbol(const struct symsearch *syms,
497 struct module *owner,
498 unsigned int symnum, void *data)
500 struct find_symbol_arg *fsa = data;
502 if (!fsa->gplok) {
503 if (syms->licence == GPL_ONLY)
504 return false;
505 if (syms->licence == WILL_BE_GPL_ONLY && fsa->warn) {
506 pr_warn("Symbol %s is being used by a non-GPL module, "
507 "which will not be allowed in the future\n",
508 fsa->name);
512 #ifdef CONFIG_UNUSED_SYMBOLS
513 if (syms->unused && fsa->warn) {
514 pr_warn("Symbol %s is marked as UNUSED, however this module is "
515 "using it.\n", fsa->name);
516 pr_warn("This symbol will go away in the future.\n");
517 pr_warn("Please evaluate if this is the right api to use and "
518 "if it really is, submit a report to the linux kernel "
519 "mailing list together with submitting your code for "
520 "inclusion.\n");
522 #endif
524 fsa->owner = owner;
525 fsa->crc = symversion(syms->crcs, symnum);
526 fsa->sym = &syms->start[symnum];
527 return true;
530 static int cmp_name(const void *va, const void *vb)
532 const char *a;
533 const struct kernel_symbol *b;
534 a = va; b = vb;
535 return strcmp(a, b->name);
538 static bool find_symbol_in_section(const struct symsearch *syms,
539 struct module *owner,
540 void *data)
542 struct find_symbol_arg *fsa = data;
543 struct kernel_symbol *sym;
545 sym = bsearch(fsa->name, syms->start, syms->stop - syms->start,
546 sizeof(struct kernel_symbol), cmp_name);
548 if (sym != NULL && check_symbol(syms, owner, sym - syms->start, data))
549 return true;
551 return false;
554 /* Find a symbol and return it, along with, (optional) crc and
555 * (optional) module which owns it. Needs preempt disabled or module_mutex. */
556 const struct kernel_symbol *find_symbol(const char *name,
557 struct module **owner,
558 const unsigned long **crc,
559 bool gplok,
560 bool warn)
562 struct find_symbol_arg fsa;
564 fsa.name = name;
565 fsa.gplok = gplok;
566 fsa.warn = warn;
568 if (each_symbol_section(find_symbol_in_section, &fsa)) {
569 if (owner)
570 *owner = fsa.owner;
571 if (crc)
572 *crc = fsa.crc;
573 return fsa.sym;
576 pr_debug("Failed to find symbol %s\n", name);
577 return NULL;
579 EXPORT_SYMBOL_GPL(find_symbol);
582 * Search for module by name: must hold module_mutex (or preempt disabled
583 * for read-only access).
585 static struct module *find_module_all(const char *name, size_t len,
586 bool even_unformed)
588 struct module *mod;
590 module_assert_mutex_or_preempt();
592 list_for_each_entry(mod, &modules, list) {
593 if (!even_unformed && mod->state == MODULE_STATE_UNFORMED)
594 continue;
595 if (strlen(mod->name) == len && !memcmp(mod->name, name, len))
596 return mod;
598 return NULL;
601 struct module *find_module(const char *name)
603 module_assert_mutex();
604 return find_module_all(name, strlen(name), false);
606 EXPORT_SYMBOL_GPL(find_module);
608 #ifdef CONFIG_SMP
610 static inline void __percpu *mod_percpu(struct module *mod)
612 return mod->percpu;
615 static int percpu_modalloc(struct module *mod, struct load_info *info)
617 Elf_Shdr *pcpusec = &info->sechdrs[info->index.pcpu];
618 unsigned long align = pcpusec->sh_addralign;
620 if (!pcpusec->sh_size)
621 return 0;
623 if (align > PAGE_SIZE) {
624 pr_warn("%s: per-cpu alignment %li > %li\n",
625 mod->name, align, PAGE_SIZE);
626 align = PAGE_SIZE;
629 mod->percpu = __alloc_reserved_percpu(pcpusec->sh_size, align);
630 if (!mod->percpu) {
631 pr_warn("%s: Could not allocate %lu bytes percpu data\n",
632 mod->name, (unsigned long)pcpusec->sh_size);
633 return -ENOMEM;
635 mod->percpu_size = pcpusec->sh_size;
636 return 0;
639 static void percpu_modfree(struct module *mod)
641 free_percpu(mod->percpu);
644 static unsigned int find_pcpusec(struct load_info *info)
646 return find_sec(info, ".data..percpu");
649 static void percpu_modcopy(struct module *mod,
650 const void *from, unsigned long size)
652 int cpu;
654 for_each_possible_cpu(cpu)
655 memcpy(per_cpu_ptr(mod->percpu, cpu), from, size);
659 * is_module_percpu_address - test whether address is from module static percpu
660 * @addr: address to test
662 * Test whether @addr belongs to module static percpu area.
664 * RETURNS:
665 * %true if @addr is from module static percpu area
667 bool is_module_percpu_address(unsigned long addr)
669 struct module *mod;
670 unsigned int cpu;
672 preempt_disable();
674 list_for_each_entry_rcu(mod, &modules, list) {
675 if (mod->state == MODULE_STATE_UNFORMED)
676 continue;
677 if (!mod->percpu_size)
678 continue;
679 for_each_possible_cpu(cpu) {
680 void *start = per_cpu_ptr(mod->percpu, cpu);
682 if ((void *)addr >= start &&
683 (void *)addr < start + mod->percpu_size) {
684 preempt_enable();
685 return true;
690 preempt_enable();
691 return false;
694 #else /* ... !CONFIG_SMP */
696 static inline void __percpu *mod_percpu(struct module *mod)
698 return NULL;
700 static int percpu_modalloc(struct module *mod, struct load_info *info)
702 /* UP modules shouldn't have this section: ENOMEM isn't quite right */
703 if (info->sechdrs[info->index.pcpu].sh_size != 0)
704 return -ENOMEM;
705 return 0;
707 static inline void percpu_modfree(struct module *mod)
710 static unsigned int find_pcpusec(struct load_info *info)
712 return 0;
714 static inline void percpu_modcopy(struct module *mod,
715 const void *from, unsigned long size)
717 /* pcpusec should be 0, and size of that section should be 0. */
718 BUG_ON(size != 0);
720 bool is_module_percpu_address(unsigned long addr)
722 return false;
725 #endif /* CONFIG_SMP */
727 #define MODINFO_ATTR(field) \
728 static void setup_modinfo_##field(struct module *mod, const char *s) \
730 mod->field = kstrdup(s, GFP_KERNEL); \
732 static ssize_t show_modinfo_##field(struct module_attribute *mattr, \
733 struct module_kobject *mk, char *buffer) \
735 return scnprintf(buffer, PAGE_SIZE, "%s\n", mk->mod->field); \
737 static int modinfo_##field##_exists(struct module *mod) \
739 return mod->field != NULL; \
741 static void free_modinfo_##field(struct module *mod) \
743 kfree(mod->field); \
744 mod->field = NULL; \
746 static struct module_attribute modinfo_##field = { \
747 .attr = { .name = __stringify(field), .mode = 0444 }, \
748 .show = show_modinfo_##field, \
749 .setup = setup_modinfo_##field, \
750 .test = modinfo_##field##_exists, \
751 .free = free_modinfo_##field, \
754 MODINFO_ATTR(version);
755 MODINFO_ATTR(srcversion);
757 static char last_unloaded_module[MODULE_NAME_LEN+1];
759 #ifdef CONFIG_MODULE_UNLOAD
761 EXPORT_TRACEPOINT_SYMBOL(module_get);
763 /* MODULE_REF_BASE is the base reference count by kmodule loader. */
764 #define MODULE_REF_BASE 1
766 /* Init the unload section of the module. */
767 static int module_unload_init(struct module *mod)
770 * Initialize reference counter to MODULE_REF_BASE.
771 * refcnt == 0 means module is going.
773 atomic_set(&mod->refcnt, MODULE_REF_BASE);
775 INIT_LIST_HEAD(&mod->source_list);
776 INIT_LIST_HEAD(&mod->target_list);
778 /* Hold reference count during initialization. */
779 atomic_inc(&mod->refcnt);
781 return 0;
784 /* Does a already use b? */
785 static int already_uses(struct module *a, struct module *b)
787 struct module_use *use;
789 list_for_each_entry(use, &b->source_list, source_list) {
790 if (use->source == a) {
791 pr_debug("%s uses %s!\n", a->name, b->name);
792 return 1;
795 pr_debug("%s does not use %s!\n", a->name, b->name);
796 return 0;
800 * Module a uses b
801 * - we add 'a' as a "source", 'b' as a "target" of module use
802 * - the module_use is added to the list of 'b' sources (so
803 * 'b' can walk the list to see who sourced them), and of 'a'
804 * targets (so 'a' can see what modules it targets).
806 static int add_module_usage(struct module *a, struct module *b)
808 struct module_use *use;
810 pr_debug("Allocating new usage for %s.\n", a->name);
811 use = kmalloc(sizeof(*use), GFP_ATOMIC);
812 if (!use) {
813 pr_warn("%s: out of memory loading\n", a->name);
814 return -ENOMEM;
817 use->source = a;
818 use->target = b;
819 list_add(&use->source_list, &b->source_list);
820 list_add(&use->target_list, &a->target_list);
821 return 0;
824 /* Module a uses b: caller needs module_mutex() */
825 int ref_module(struct module *a, struct module *b)
827 int err;
829 if (b == NULL || already_uses(a, b))
830 return 0;
832 /* If module isn't available, we fail. */
833 err = strong_try_module_get(b);
834 if (err)
835 return err;
837 err = add_module_usage(a, b);
838 if (err) {
839 module_put(b);
840 return err;
842 return 0;
844 EXPORT_SYMBOL_GPL(ref_module);
846 /* Clear the unload stuff of the module. */
847 static void module_unload_free(struct module *mod)
849 struct module_use *use, *tmp;
851 mutex_lock(&module_mutex);
852 list_for_each_entry_safe(use, tmp, &mod->target_list, target_list) {
853 struct module *i = use->target;
854 pr_debug("%s unusing %s\n", mod->name, i->name);
855 module_put(i);
856 list_del(&use->source_list);
857 list_del(&use->target_list);
858 kfree(use);
860 mutex_unlock(&module_mutex);
863 #ifdef CONFIG_MODULE_FORCE_UNLOAD
864 static inline int try_force_unload(unsigned int flags)
866 int ret = (flags & O_TRUNC);
867 if (ret)
868 add_taint(TAINT_FORCED_RMMOD, LOCKDEP_NOW_UNRELIABLE);
869 return ret;
871 #else
872 static inline int try_force_unload(unsigned int flags)
874 return 0;
876 #endif /* CONFIG_MODULE_FORCE_UNLOAD */
878 /* Try to release refcount of module, 0 means success. */
879 static int try_release_module_ref(struct module *mod)
881 int ret;
883 /* Try to decrement refcnt which we set at loading */
884 ret = atomic_sub_return(MODULE_REF_BASE, &mod->refcnt);
885 BUG_ON(ret < 0);
886 if (ret)
887 /* Someone can put this right now, recover with checking */
888 ret = atomic_add_unless(&mod->refcnt, MODULE_REF_BASE, 0);
890 return ret;
893 static int try_stop_module(struct module *mod, int flags, int *forced)
895 /* If it's not unused, quit unless we're forcing. */
896 if (try_release_module_ref(mod) != 0) {
897 *forced = try_force_unload(flags);
898 if (!(*forced))
899 return -EWOULDBLOCK;
902 /* Mark it as dying. */
903 mod->state = MODULE_STATE_GOING;
905 return 0;
909 * module_refcount - return the refcount or -1 if unloading
911 * @mod: the module we're checking
913 * Returns:
914 * -1 if the module is in the process of unloading
915 * otherwise the number of references in the kernel to the module
917 int module_refcount(struct module *mod)
919 return atomic_read(&mod->refcnt) - MODULE_REF_BASE;
921 EXPORT_SYMBOL(module_refcount);
923 /* This exists whether we can unload or not */
924 static void free_module(struct module *mod);
926 SYSCALL_DEFINE2(delete_module, const char __user *, name_user,
927 unsigned int, flags)
929 struct module *mod;
930 char name[MODULE_NAME_LEN];
931 int ret, forced = 0;
933 if (!capable(CAP_SYS_MODULE) || modules_disabled)
934 return -EPERM;
936 if (strncpy_from_user(name, name_user, MODULE_NAME_LEN-1) < 0)
937 return -EFAULT;
938 name[MODULE_NAME_LEN-1] = '\0';
940 if (mutex_lock_interruptible(&module_mutex) != 0)
941 return -EINTR;
943 mod = find_module(name);
944 if (!mod) {
945 ret = -ENOENT;
946 goto out;
949 if (!list_empty(&mod->source_list)) {
950 /* Other modules depend on us: get rid of them first. */
951 ret = -EWOULDBLOCK;
952 goto out;
955 /* Doing init or already dying? */
956 if (mod->state != MODULE_STATE_LIVE) {
957 /* FIXME: if (force), slam module count damn the torpedoes */
958 pr_debug("%s already dying\n", mod->name);
959 ret = -EBUSY;
960 goto out;
963 /* If it has an init func, it must have an exit func to unload */
964 if (mod->init && !mod->exit) {
965 forced = try_force_unload(flags);
966 if (!forced) {
967 /* This module can't be removed */
968 ret = -EBUSY;
969 goto out;
973 /* Stop the machine so refcounts can't move and disable module. */
974 ret = try_stop_module(mod, flags, &forced);
975 if (ret != 0)
976 goto out;
978 mutex_unlock(&module_mutex);
979 /* Final destruction now no one is using it. */
980 if (mod->exit != NULL)
981 mod->exit();
982 blocking_notifier_call_chain(&module_notify_list,
983 MODULE_STATE_GOING, mod);
984 async_synchronize_full();
986 /* Store the name of the last unloaded module for diagnostic purposes */
987 strlcpy(last_unloaded_module, mod->name, sizeof(last_unloaded_module));
989 free_module(mod);
990 return 0;
991 out:
992 mutex_unlock(&module_mutex);
993 return ret;
996 static inline void print_unload_info(struct seq_file *m, struct module *mod)
998 struct module_use *use;
999 int printed_something = 0;
1001 seq_printf(m, " %i ", module_refcount(mod));
1004 * Always include a trailing , so userspace can differentiate
1005 * between this and the old multi-field proc format.
1007 list_for_each_entry(use, &mod->source_list, source_list) {
1008 printed_something = 1;
1009 seq_printf(m, "%s,", use->source->name);
1012 if (mod->init != NULL && mod->exit == NULL) {
1013 printed_something = 1;
1014 seq_puts(m, "[permanent],");
1017 if (!printed_something)
1018 seq_puts(m, "-");
1021 void __symbol_put(const char *symbol)
1023 struct module *owner;
1025 preempt_disable();
1026 if (!find_symbol(symbol, &owner, NULL, true, false))
1027 BUG();
1028 module_put(owner);
1029 preempt_enable();
1031 EXPORT_SYMBOL(__symbol_put);
1033 /* Note this assumes addr is a function, which it currently always is. */
1034 void symbol_put_addr(void *addr)
1036 struct module *modaddr;
1037 unsigned long a = (unsigned long)dereference_function_descriptor(addr);
1039 if (core_kernel_text(a))
1040 return;
1043 * Even though we hold a reference on the module; we still need to
1044 * disable preemption in order to safely traverse the data structure.
1046 preempt_disable();
1047 modaddr = __module_text_address(a);
1048 BUG_ON(!modaddr);
1049 module_put(modaddr);
1050 preempt_enable();
1052 EXPORT_SYMBOL_GPL(symbol_put_addr);
1054 static ssize_t show_refcnt(struct module_attribute *mattr,
1055 struct module_kobject *mk, char *buffer)
1057 return sprintf(buffer, "%i\n", module_refcount(mk->mod));
1060 static struct module_attribute modinfo_refcnt =
1061 __ATTR(refcnt, 0444, show_refcnt, NULL);
1063 void __module_get(struct module *module)
1065 if (module) {
1066 preempt_disable();
1067 atomic_inc(&module->refcnt);
1068 trace_module_get(module, _RET_IP_);
1069 preempt_enable();
1072 EXPORT_SYMBOL(__module_get);
1074 bool try_module_get(struct module *module)
1076 bool ret = true;
1078 if (module) {
1079 preempt_disable();
1080 /* Note: here, we can fail to get a reference */
1081 if (likely(module_is_live(module) &&
1082 atomic_inc_not_zero(&module->refcnt) != 0))
1083 trace_module_get(module, _RET_IP_);
1084 else
1085 ret = false;
1087 preempt_enable();
1089 return ret;
1091 EXPORT_SYMBOL(try_module_get);
1093 void module_put(struct module *module)
1095 int ret;
1097 if (module) {
1098 preempt_disable();
1099 ret = atomic_dec_if_positive(&module->refcnt);
1100 WARN_ON(ret < 0); /* Failed to put refcount */
1101 trace_module_put(module, _RET_IP_);
1102 preempt_enable();
1105 EXPORT_SYMBOL(module_put);
1107 #else /* !CONFIG_MODULE_UNLOAD */
1108 static inline void print_unload_info(struct seq_file *m, struct module *mod)
1110 /* We don't know the usage count, or what modules are using. */
1111 seq_puts(m, " - -");
1114 static inline void module_unload_free(struct module *mod)
1118 int ref_module(struct module *a, struct module *b)
1120 return strong_try_module_get(b);
1122 EXPORT_SYMBOL_GPL(ref_module);
1124 static inline int module_unload_init(struct module *mod)
1126 return 0;
1128 #endif /* CONFIG_MODULE_UNLOAD */
1130 static size_t module_flags_taint(struct module *mod, char *buf)
1132 size_t l = 0;
1134 if (mod->taints & (1 << TAINT_PROPRIETARY_MODULE))
1135 buf[l++] = 'P';
1136 if (mod->taints & (1 << TAINT_OOT_MODULE))
1137 buf[l++] = 'O';
1138 if (mod->taints & (1 << TAINT_FORCED_MODULE))
1139 buf[l++] = 'F';
1140 if (mod->taints & (1 << TAINT_CRAP))
1141 buf[l++] = 'C';
1142 if (mod->taints & (1 << TAINT_UNSIGNED_MODULE))
1143 buf[l++] = 'E';
1145 * TAINT_FORCED_RMMOD: could be added.
1146 * TAINT_CPU_OUT_OF_SPEC, TAINT_MACHINE_CHECK, TAINT_BAD_PAGE don't
1147 * apply to modules.
1149 return l;
1152 static ssize_t show_initstate(struct module_attribute *mattr,
1153 struct module_kobject *mk, char *buffer)
1155 const char *state = "unknown";
1157 switch (mk->mod->state) {
1158 case MODULE_STATE_LIVE:
1159 state = "live";
1160 break;
1161 case MODULE_STATE_COMING:
1162 state = "coming";
1163 break;
1164 case MODULE_STATE_GOING:
1165 state = "going";
1166 break;
1167 default:
1168 BUG();
1170 return sprintf(buffer, "%s\n", state);
1173 static struct module_attribute modinfo_initstate =
1174 __ATTR(initstate, 0444, show_initstate, NULL);
1176 static ssize_t store_uevent(struct module_attribute *mattr,
1177 struct module_kobject *mk,
1178 const char *buffer, size_t count)
1180 enum kobject_action action;
1182 if (kobject_action_type(buffer, count, &action) == 0)
1183 kobject_uevent(&mk->kobj, action);
1184 return count;
1187 struct module_attribute module_uevent =
1188 __ATTR(uevent, 0200, NULL, store_uevent);
1190 static ssize_t show_coresize(struct module_attribute *mattr,
1191 struct module_kobject *mk, char *buffer)
1193 return sprintf(buffer, "%u\n", mk->mod->core_layout.size);
1196 static struct module_attribute modinfo_coresize =
1197 __ATTR(coresize, 0444, show_coresize, NULL);
1199 static ssize_t show_initsize(struct module_attribute *mattr,
1200 struct module_kobject *mk, char *buffer)
1202 return sprintf(buffer, "%u\n", mk->mod->init_layout.size);
1205 static struct module_attribute modinfo_initsize =
1206 __ATTR(initsize, 0444, show_initsize, NULL);
1208 static ssize_t show_taint(struct module_attribute *mattr,
1209 struct module_kobject *mk, char *buffer)
1211 size_t l;
1213 l = module_flags_taint(mk->mod, buffer);
1214 buffer[l++] = '\n';
1215 return l;
1218 static struct module_attribute modinfo_taint =
1219 __ATTR(taint, 0444, show_taint, NULL);
1221 static struct module_attribute *modinfo_attrs[] = {
1222 &module_uevent,
1223 &modinfo_version,
1224 &modinfo_srcversion,
1225 &modinfo_initstate,
1226 &modinfo_coresize,
1227 &modinfo_initsize,
1228 &modinfo_taint,
1229 #ifdef CONFIG_MODULE_UNLOAD
1230 &modinfo_refcnt,
1231 #endif
1232 NULL,
1235 static const char vermagic[] = VERMAGIC_STRING;
1237 static int try_to_force_load(struct module *mod, const char *reason)
1239 #ifdef CONFIG_MODULE_FORCE_LOAD
1240 if (!test_taint(TAINT_FORCED_MODULE))
1241 pr_warn("%s: %s: kernel tainted.\n", mod->name, reason);
1242 add_taint_module(mod, TAINT_FORCED_MODULE, LOCKDEP_NOW_UNRELIABLE);
1243 return 0;
1244 #else
1245 return -ENOEXEC;
1246 #endif
1249 #ifdef CONFIG_MODVERSIONS
1250 /* If the arch applies (non-zero) relocations to kernel kcrctab, unapply it. */
1251 static unsigned long maybe_relocated(unsigned long crc,
1252 const struct module *crc_owner)
1254 #ifdef ARCH_RELOCATES_KCRCTAB
1255 if (crc_owner == NULL)
1256 return crc - (unsigned long)reloc_start;
1257 #endif
1258 return crc;
1261 static int check_version(Elf_Shdr *sechdrs,
1262 unsigned int versindex,
1263 const char *symname,
1264 struct module *mod,
1265 const unsigned long *crc,
1266 const struct module *crc_owner)
1268 unsigned int i, num_versions;
1269 struct modversion_info *versions;
1271 /* Exporting module didn't supply crcs? OK, we're already tainted. */
1272 if (!crc)
1273 return 1;
1275 /* No versions at all? modprobe --force does this. */
1276 if (versindex == 0)
1277 return try_to_force_load(mod, symname) == 0;
1279 versions = (void *) sechdrs[versindex].sh_addr;
1280 num_versions = sechdrs[versindex].sh_size
1281 / sizeof(struct modversion_info);
1283 for (i = 0; i < num_versions; i++) {
1284 if (strcmp(versions[i].name, symname) != 0)
1285 continue;
1287 if (versions[i].crc == maybe_relocated(*crc, crc_owner))
1288 return 1;
1289 pr_debug("Found checksum %lX vs module %lX\n",
1290 maybe_relocated(*crc, crc_owner), versions[i].crc);
1291 goto bad_version;
1294 pr_warn("%s: no symbol version for %s\n", mod->name, symname);
1295 return 0;
1297 bad_version:
1298 pr_warn("%s: disagrees about version of symbol %s\n",
1299 mod->name, symname);
1300 return 0;
1303 static inline int check_modstruct_version(Elf_Shdr *sechdrs,
1304 unsigned int versindex,
1305 struct module *mod)
1307 const unsigned long *crc;
1310 * Since this should be found in kernel (which can't be removed), no
1311 * locking is necessary -- use preempt_disable() to placate lockdep.
1313 preempt_disable();
1314 if (!find_symbol(VMLINUX_SYMBOL_STR(module_layout), NULL,
1315 &crc, true, false)) {
1316 preempt_enable();
1317 BUG();
1319 preempt_enable();
1320 return check_version(sechdrs, versindex,
1321 VMLINUX_SYMBOL_STR(module_layout), mod, crc,
1322 NULL);
1325 /* First part is kernel version, which we ignore if module has crcs. */
1326 static inline int same_magic(const char *amagic, const char *bmagic,
1327 bool has_crcs)
1329 if (has_crcs) {
1330 amagic += strcspn(amagic, " ");
1331 bmagic += strcspn(bmagic, " ");
1333 return strcmp(amagic, bmagic) == 0;
1335 #else
1336 static inline int check_version(Elf_Shdr *sechdrs,
1337 unsigned int versindex,
1338 const char *symname,
1339 struct module *mod,
1340 const unsigned long *crc,
1341 const struct module *crc_owner)
1343 return 1;
1346 static inline int check_modstruct_version(Elf_Shdr *sechdrs,
1347 unsigned int versindex,
1348 struct module *mod)
1350 return 1;
1353 static inline int same_magic(const char *amagic, const char *bmagic,
1354 bool has_crcs)
1356 return strcmp(amagic, bmagic) == 0;
1358 #endif /* CONFIG_MODVERSIONS */
1360 /* Resolve a symbol for this module. I.e. if we find one, record usage. */
1361 static const struct kernel_symbol *resolve_symbol(struct module *mod,
1362 const struct load_info *info,
1363 const char *name,
1364 char ownername[])
1366 struct module *owner;
1367 const struct kernel_symbol *sym;
1368 const unsigned long *crc;
1369 int err;
1372 * The module_mutex should not be a heavily contended lock;
1373 * if we get the occasional sleep here, we'll go an extra iteration
1374 * in the wait_event_interruptible(), which is harmless.
1376 sched_annotate_sleep();
1377 mutex_lock(&module_mutex);
1378 sym = find_symbol(name, &owner, &crc,
1379 !(mod->taints & (1 << TAINT_PROPRIETARY_MODULE)), true);
1380 if (!sym)
1381 goto unlock;
1383 if (!check_version(info->sechdrs, info->index.vers, name, mod, crc,
1384 owner)) {
1385 sym = ERR_PTR(-EINVAL);
1386 goto getname;
1389 err = ref_module(mod, owner);
1390 if (err) {
1391 sym = ERR_PTR(err);
1392 goto getname;
1395 getname:
1396 /* We must make copy under the lock if we failed to get ref. */
1397 strncpy(ownername, module_name(owner), MODULE_NAME_LEN);
1398 unlock:
1399 mutex_unlock(&module_mutex);
1400 return sym;
1403 static const struct kernel_symbol *
1404 resolve_symbol_wait(struct module *mod,
1405 const struct load_info *info,
1406 const char *name)
1408 const struct kernel_symbol *ksym;
1409 char owner[MODULE_NAME_LEN];
1411 if (wait_event_interruptible_timeout(module_wq,
1412 !IS_ERR(ksym = resolve_symbol(mod, info, name, owner))
1413 || PTR_ERR(ksym) != -EBUSY,
1414 30 * HZ) <= 0) {
1415 pr_warn("%s: gave up waiting for init of module %s.\n",
1416 mod->name, owner);
1418 return ksym;
1422 * /sys/module/foo/sections stuff
1423 * J. Corbet <corbet@lwn.net>
1425 #ifdef CONFIG_SYSFS
1427 #ifdef CONFIG_KALLSYMS
1428 static inline bool sect_empty(const Elf_Shdr *sect)
1430 return !(sect->sh_flags & SHF_ALLOC) || sect->sh_size == 0;
1433 struct module_sect_attr {
1434 struct module_attribute mattr;
1435 char *name;
1436 unsigned long address;
1439 struct module_sect_attrs {
1440 struct attribute_group grp;
1441 unsigned int nsections;
1442 struct module_sect_attr attrs[0];
1445 static ssize_t module_sect_show(struct module_attribute *mattr,
1446 struct module_kobject *mk, char *buf)
1448 struct module_sect_attr *sattr =
1449 container_of(mattr, struct module_sect_attr, mattr);
1450 return sprintf(buf, "0x%pK\n", (void *)sattr->address);
1453 static void free_sect_attrs(struct module_sect_attrs *sect_attrs)
1455 unsigned int section;
1457 for (section = 0; section < sect_attrs->nsections; section++)
1458 kfree(sect_attrs->attrs[section].name);
1459 kfree(sect_attrs);
1462 static void add_sect_attrs(struct module *mod, const struct load_info *info)
1464 unsigned int nloaded = 0, i, size[2];
1465 struct module_sect_attrs *sect_attrs;
1466 struct module_sect_attr *sattr;
1467 struct attribute **gattr;
1469 /* Count loaded sections and allocate structures */
1470 for (i = 0; i < info->hdr->e_shnum; i++)
1471 if (!sect_empty(&info->sechdrs[i]))
1472 nloaded++;
1473 size[0] = ALIGN(sizeof(*sect_attrs)
1474 + nloaded * sizeof(sect_attrs->attrs[0]),
1475 sizeof(sect_attrs->grp.attrs[0]));
1476 size[1] = (nloaded + 1) * sizeof(sect_attrs->grp.attrs[0]);
1477 sect_attrs = kzalloc(size[0] + size[1], GFP_KERNEL);
1478 if (sect_attrs == NULL)
1479 return;
1481 /* Setup section attributes. */
1482 sect_attrs->grp.name = "sections";
1483 sect_attrs->grp.attrs = (void *)sect_attrs + size[0];
1485 sect_attrs->nsections = 0;
1486 sattr = &sect_attrs->attrs[0];
1487 gattr = &sect_attrs->grp.attrs[0];
1488 for (i = 0; i < info->hdr->e_shnum; i++) {
1489 Elf_Shdr *sec = &info->sechdrs[i];
1490 if (sect_empty(sec))
1491 continue;
1492 sattr->address = sec->sh_addr;
1493 sattr->name = kstrdup(info->secstrings + sec->sh_name,
1494 GFP_KERNEL);
1495 if (sattr->name == NULL)
1496 goto out;
1497 sect_attrs->nsections++;
1498 sysfs_attr_init(&sattr->mattr.attr);
1499 sattr->mattr.show = module_sect_show;
1500 sattr->mattr.store = NULL;
1501 sattr->mattr.attr.name = sattr->name;
1502 sattr->mattr.attr.mode = S_IRUGO;
1503 *(gattr++) = &(sattr++)->mattr.attr;
1505 *gattr = NULL;
1507 if (sysfs_create_group(&mod->mkobj.kobj, &sect_attrs->grp))
1508 goto out;
1510 mod->sect_attrs = sect_attrs;
1511 return;
1512 out:
1513 free_sect_attrs(sect_attrs);
1516 static void remove_sect_attrs(struct module *mod)
1518 if (mod->sect_attrs) {
1519 sysfs_remove_group(&mod->mkobj.kobj,
1520 &mod->sect_attrs->grp);
1521 /* We are positive that no one is using any sect attrs
1522 * at this point. Deallocate immediately. */
1523 free_sect_attrs(mod->sect_attrs);
1524 mod->sect_attrs = NULL;
1529 * /sys/module/foo/notes/.section.name gives contents of SHT_NOTE sections.
1532 struct module_notes_attrs {
1533 struct kobject *dir;
1534 unsigned int notes;
1535 struct bin_attribute attrs[0];
1538 static ssize_t module_notes_read(struct file *filp, struct kobject *kobj,
1539 struct bin_attribute *bin_attr,
1540 char *buf, loff_t pos, size_t count)
1543 * The caller checked the pos and count against our size.
1545 memcpy(buf, bin_attr->private + pos, count);
1546 return count;
1549 static void free_notes_attrs(struct module_notes_attrs *notes_attrs,
1550 unsigned int i)
1552 if (notes_attrs->dir) {
1553 while (i-- > 0)
1554 sysfs_remove_bin_file(notes_attrs->dir,
1555 &notes_attrs->attrs[i]);
1556 kobject_put(notes_attrs->dir);
1558 kfree(notes_attrs);
1561 static void add_notes_attrs(struct module *mod, const struct load_info *info)
1563 unsigned int notes, loaded, i;
1564 struct module_notes_attrs *notes_attrs;
1565 struct bin_attribute *nattr;
1567 /* failed to create section attributes, so can't create notes */
1568 if (!mod->sect_attrs)
1569 return;
1571 /* Count notes sections and allocate structures. */
1572 notes = 0;
1573 for (i = 0; i < info->hdr->e_shnum; i++)
1574 if (!sect_empty(&info->sechdrs[i]) &&
1575 (info->sechdrs[i].sh_type == SHT_NOTE))
1576 ++notes;
1578 if (notes == 0)
1579 return;
1581 notes_attrs = kzalloc(sizeof(*notes_attrs)
1582 + notes * sizeof(notes_attrs->attrs[0]),
1583 GFP_KERNEL);
1584 if (notes_attrs == NULL)
1585 return;
1587 notes_attrs->notes = notes;
1588 nattr = &notes_attrs->attrs[0];
1589 for (loaded = i = 0; i < info->hdr->e_shnum; ++i) {
1590 if (sect_empty(&info->sechdrs[i]))
1591 continue;
1592 if (info->sechdrs[i].sh_type == SHT_NOTE) {
1593 sysfs_bin_attr_init(nattr);
1594 nattr->attr.name = mod->sect_attrs->attrs[loaded].name;
1595 nattr->attr.mode = S_IRUGO;
1596 nattr->size = info->sechdrs[i].sh_size;
1597 nattr->private = (void *) info->sechdrs[i].sh_addr;
1598 nattr->read = module_notes_read;
1599 ++nattr;
1601 ++loaded;
1604 notes_attrs->dir = kobject_create_and_add("notes", &mod->mkobj.kobj);
1605 if (!notes_attrs->dir)
1606 goto out;
1608 for (i = 0; i < notes; ++i)
1609 if (sysfs_create_bin_file(notes_attrs->dir,
1610 &notes_attrs->attrs[i]))
1611 goto out;
1613 mod->notes_attrs = notes_attrs;
1614 return;
1616 out:
1617 free_notes_attrs(notes_attrs, i);
1620 static void remove_notes_attrs(struct module *mod)
1622 if (mod->notes_attrs)
1623 free_notes_attrs(mod->notes_attrs, mod->notes_attrs->notes);
1626 #else
1628 static inline void add_sect_attrs(struct module *mod,
1629 const struct load_info *info)
1633 static inline void remove_sect_attrs(struct module *mod)
1637 static inline void add_notes_attrs(struct module *mod,
1638 const struct load_info *info)
1642 static inline void remove_notes_attrs(struct module *mod)
1645 #endif /* CONFIG_KALLSYMS */
1647 static void add_usage_links(struct module *mod)
1649 #ifdef CONFIG_MODULE_UNLOAD
1650 struct module_use *use;
1651 int nowarn;
1653 mutex_lock(&module_mutex);
1654 list_for_each_entry(use, &mod->target_list, target_list) {
1655 nowarn = sysfs_create_link(use->target->holders_dir,
1656 &mod->mkobj.kobj, mod->name);
1658 mutex_unlock(&module_mutex);
1659 #endif
1662 static void del_usage_links(struct module *mod)
1664 #ifdef CONFIG_MODULE_UNLOAD
1665 struct module_use *use;
1667 mutex_lock(&module_mutex);
1668 list_for_each_entry(use, &mod->target_list, target_list)
1669 sysfs_remove_link(use->target->holders_dir, mod->name);
1670 mutex_unlock(&module_mutex);
1671 #endif
1674 static int module_add_modinfo_attrs(struct module *mod)
1676 struct module_attribute *attr;
1677 struct module_attribute *temp_attr;
1678 int error = 0;
1679 int i;
1681 mod->modinfo_attrs = kzalloc((sizeof(struct module_attribute) *
1682 (ARRAY_SIZE(modinfo_attrs) + 1)),
1683 GFP_KERNEL);
1684 if (!mod->modinfo_attrs)
1685 return -ENOMEM;
1687 temp_attr = mod->modinfo_attrs;
1688 for (i = 0; (attr = modinfo_attrs[i]) && !error; i++) {
1689 if (!attr->test ||
1690 (attr->test && attr->test(mod))) {
1691 memcpy(temp_attr, attr, sizeof(*temp_attr));
1692 sysfs_attr_init(&temp_attr->attr);
1693 error = sysfs_create_file(&mod->mkobj.kobj,
1694 &temp_attr->attr);
1695 ++temp_attr;
1698 return error;
1701 static void module_remove_modinfo_attrs(struct module *mod)
1703 struct module_attribute *attr;
1704 int i;
1706 for (i = 0; (attr = &mod->modinfo_attrs[i]); i++) {
1707 /* pick a field to test for end of list */
1708 if (!attr->attr.name)
1709 break;
1710 sysfs_remove_file(&mod->mkobj.kobj, &attr->attr);
1711 if (attr->free)
1712 attr->free(mod);
1714 kfree(mod->modinfo_attrs);
1717 static void mod_kobject_put(struct module *mod)
1719 DECLARE_COMPLETION_ONSTACK(c);
1720 mod->mkobj.kobj_completion = &c;
1721 kobject_put(&mod->mkobj.kobj);
1722 wait_for_completion(&c);
1725 static int mod_sysfs_init(struct module *mod)
1727 int err;
1728 struct kobject *kobj;
1730 if (!module_sysfs_initialized) {
1731 pr_err("%s: module sysfs not initialized\n", mod->name);
1732 err = -EINVAL;
1733 goto out;
1736 kobj = kset_find_obj(module_kset, mod->name);
1737 if (kobj) {
1738 pr_err("%s: module is already loaded\n", mod->name);
1739 kobject_put(kobj);
1740 err = -EINVAL;
1741 goto out;
1744 mod->mkobj.mod = mod;
1746 memset(&mod->mkobj.kobj, 0, sizeof(mod->mkobj.kobj));
1747 mod->mkobj.kobj.kset = module_kset;
1748 err = kobject_init_and_add(&mod->mkobj.kobj, &module_ktype, NULL,
1749 "%s", mod->name);
1750 if (err)
1751 mod_kobject_put(mod);
1753 /* delay uevent until full sysfs population */
1754 out:
1755 return err;
1758 static int mod_sysfs_setup(struct module *mod,
1759 const struct load_info *info,
1760 struct kernel_param *kparam,
1761 unsigned int num_params)
1763 int err;
1765 err = mod_sysfs_init(mod);
1766 if (err)
1767 goto out;
1769 mod->holders_dir = kobject_create_and_add("holders", &mod->mkobj.kobj);
1770 if (!mod->holders_dir) {
1771 err = -ENOMEM;
1772 goto out_unreg;
1775 err = module_param_sysfs_setup(mod, kparam, num_params);
1776 if (err)
1777 goto out_unreg_holders;
1779 err = module_add_modinfo_attrs(mod);
1780 if (err)
1781 goto out_unreg_param;
1783 add_usage_links(mod);
1784 add_sect_attrs(mod, info);
1785 add_notes_attrs(mod, info);
1787 kobject_uevent(&mod->mkobj.kobj, KOBJ_ADD);
1788 return 0;
1790 out_unreg_param:
1791 module_param_sysfs_remove(mod);
1792 out_unreg_holders:
1793 kobject_put(mod->holders_dir);
1794 out_unreg:
1795 mod_kobject_put(mod);
1796 out:
1797 return err;
1800 static void mod_sysfs_fini(struct module *mod)
1802 remove_notes_attrs(mod);
1803 remove_sect_attrs(mod);
1804 mod_kobject_put(mod);
1807 static void init_param_lock(struct module *mod)
1809 mutex_init(&mod->param_lock);
1811 #else /* !CONFIG_SYSFS */
1813 static int mod_sysfs_setup(struct module *mod,
1814 const struct load_info *info,
1815 struct kernel_param *kparam,
1816 unsigned int num_params)
1818 return 0;
1821 static void mod_sysfs_fini(struct module *mod)
1825 static void module_remove_modinfo_attrs(struct module *mod)
1829 static void del_usage_links(struct module *mod)
1833 static void init_param_lock(struct module *mod)
1836 #endif /* CONFIG_SYSFS */
1838 static void mod_sysfs_teardown(struct module *mod)
1840 del_usage_links(mod);
1841 module_remove_modinfo_attrs(mod);
1842 module_param_sysfs_remove(mod);
1843 kobject_put(mod->mkobj.drivers_dir);
1844 kobject_put(mod->holders_dir);
1845 mod_sysfs_fini(mod);
1848 #ifdef CONFIG_DEBUG_SET_MODULE_RONX
1850 * LKM RO/NX protection: protect module's text/ro-data
1851 * from modification and any data from execution.
1853 * General layout of module is:
1854 * [text] [read-only-data] [writable data]
1855 * text_size -----^ ^ ^
1856 * ro_size ------------------------| |
1857 * size -------------------------------------------|
1859 * These values are always page-aligned (as is base)
1861 static void frob_text(const struct module_layout *layout,
1862 int (*set_memory)(unsigned long start, int num_pages))
1864 BUG_ON((unsigned long)layout->base & (PAGE_SIZE-1));
1865 BUG_ON((unsigned long)layout->text_size & (PAGE_SIZE-1));
1866 set_memory((unsigned long)layout->base,
1867 layout->text_size >> PAGE_SHIFT);
1870 static void frob_rodata(const struct module_layout *layout,
1871 int (*set_memory)(unsigned long start, int num_pages))
1873 BUG_ON((unsigned long)layout->base & (PAGE_SIZE-1));
1874 BUG_ON((unsigned long)layout->text_size & (PAGE_SIZE-1));
1875 BUG_ON((unsigned long)layout->ro_size & (PAGE_SIZE-1));
1876 set_memory((unsigned long)layout->base + layout->text_size,
1877 (layout->ro_size - layout->text_size) >> PAGE_SHIFT);
1880 static void frob_writable_data(const struct module_layout *layout,
1881 int (*set_memory)(unsigned long start, int num_pages))
1883 BUG_ON((unsigned long)layout->base & (PAGE_SIZE-1));
1884 BUG_ON((unsigned long)layout->ro_size & (PAGE_SIZE-1));
1885 BUG_ON((unsigned long)layout->size & (PAGE_SIZE-1));
1886 set_memory((unsigned long)layout->base + layout->ro_size,
1887 (layout->size - layout->ro_size) >> PAGE_SHIFT);
1890 /* livepatching wants to disable read-only so it can frob module. */
1891 void module_disable_ro(const struct module *mod)
1893 frob_text(&mod->core_layout, set_memory_rw);
1894 frob_rodata(&mod->core_layout, set_memory_rw);
1895 frob_text(&mod->init_layout, set_memory_rw);
1896 frob_rodata(&mod->init_layout, set_memory_rw);
1899 void module_enable_ro(const struct module *mod)
1901 frob_text(&mod->core_layout, set_memory_ro);
1902 frob_rodata(&mod->core_layout, set_memory_ro);
1903 frob_text(&mod->init_layout, set_memory_ro);
1904 frob_rodata(&mod->init_layout, set_memory_ro);
1907 static void module_enable_nx(const struct module *mod)
1909 frob_rodata(&mod->core_layout, set_memory_nx);
1910 frob_writable_data(&mod->core_layout, set_memory_nx);
1911 frob_rodata(&mod->init_layout, set_memory_nx);
1912 frob_writable_data(&mod->init_layout, set_memory_nx);
1915 static void module_disable_nx(const struct module *mod)
1917 frob_rodata(&mod->core_layout, set_memory_x);
1918 frob_writable_data(&mod->core_layout, set_memory_x);
1919 frob_rodata(&mod->init_layout, set_memory_x);
1920 frob_writable_data(&mod->init_layout, set_memory_x);
1923 /* Iterate through all modules and set each module's text as RW */
1924 void set_all_modules_text_rw(void)
1926 struct module *mod;
1928 mutex_lock(&module_mutex);
1929 list_for_each_entry_rcu(mod, &modules, list) {
1930 if (mod->state == MODULE_STATE_UNFORMED)
1931 continue;
1933 frob_text(&mod->core_layout, set_memory_rw);
1934 frob_text(&mod->init_layout, set_memory_rw);
1936 mutex_unlock(&module_mutex);
1939 /* Iterate through all modules and set each module's text as RO */
1940 void set_all_modules_text_ro(void)
1942 struct module *mod;
1944 mutex_lock(&module_mutex);
1945 list_for_each_entry_rcu(mod, &modules, list) {
1946 if (mod->state == MODULE_STATE_UNFORMED)
1947 continue;
1949 frob_text(&mod->core_layout, set_memory_ro);
1950 frob_text(&mod->init_layout, set_memory_ro);
1952 mutex_unlock(&module_mutex);
1955 static void disable_ro_nx(const struct module_layout *layout)
1957 frob_text(layout, set_memory_rw);
1958 frob_rodata(layout, set_memory_rw);
1959 frob_rodata(layout, set_memory_x);
1960 frob_writable_data(layout, set_memory_x);
1963 #else
1964 static void disable_ro_nx(const struct module_layout *layout) { }
1965 static void module_enable_nx(const struct module *mod) { }
1966 static void module_disable_nx(const struct module *mod) { }
1967 #endif
1969 void __weak module_memfree(void *module_region)
1971 vfree(module_region);
1974 void __weak module_arch_cleanup(struct module *mod)
1978 void __weak module_arch_freeing_init(struct module *mod)
1982 /* Free a module, remove from lists, etc. */
1983 static void free_module(struct module *mod)
1985 trace_module_free(mod);
1987 mod_sysfs_teardown(mod);
1989 /* We leave it in list to prevent duplicate loads, but make sure
1990 * that noone uses it while it's being deconstructed. */
1991 mutex_lock(&module_mutex);
1992 mod->state = MODULE_STATE_UNFORMED;
1993 mutex_unlock(&module_mutex);
1995 /* Remove dynamic debug info */
1996 ddebug_remove_module(mod->name);
1998 /* Arch-specific cleanup. */
1999 module_arch_cleanup(mod);
2001 /* Module unload stuff */
2002 module_unload_free(mod);
2004 /* Free any allocated parameters. */
2005 destroy_params(mod->kp, mod->num_kp);
2007 /* Now we can delete it from the lists */
2008 mutex_lock(&module_mutex);
2009 /* Unlink carefully: kallsyms could be walking list. */
2010 list_del_rcu(&mod->list);
2011 mod_tree_remove(mod);
2012 /* Remove this module from bug list, this uses list_del_rcu */
2013 module_bug_cleanup(mod);
2014 /* Wait for RCU-sched synchronizing before releasing mod->list and buglist. */
2015 synchronize_sched();
2016 mutex_unlock(&module_mutex);
2018 /* This may be empty, but that's OK */
2019 disable_ro_nx(&mod->init_layout);
2020 module_arch_freeing_init(mod);
2021 module_memfree(mod->init_layout.base);
2022 kfree(mod->args);
2023 percpu_modfree(mod);
2025 /* Free lock-classes; relies on the preceding sync_rcu(). */
2026 lockdep_free_key_range(mod->core_layout.base, mod->core_layout.size);
2028 /* Finally, free the core (containing the module structure) */
2029 disable_ro_nx(&mod->core_layout);
2030 module_memfree(mod->core_layout.base);
2032 #ifdef CONFIG_MPU
2033 update_protections(current->mm);
2034 #endif
2037 void *__symbol_get(const char *symbol)
2039 struct module *owner;
2040 const struct kernel_symbol *sym;
2042 preempt_disable();
2043 sym = find_symbol(symbol, &owner, NULL, true, true);
2044 if (sym && strong_try_module_get(owner))
2045 sym = NULL;
2046 preempt_enable();
2048 return sym ? (void *)sym->value : NULL;
2050 EXPORT_SYMBOL_GPL(__symbol_get);
2053 * Ensure that an exported symbol [global namespace] does not already exist
2054 * in the kernel or in some other module's exported symbol table.
2056 * You must hold the module_mutex.
2058 static int verify_export_symbols(struct module *mod)
2060 unsigned int i;
2061 struct module *owner;
2062 const struct kernel_symbol *s;
2063 struct {
2064 const struct kernel_symbol *sym;
2065 unsigned int num;
2066 } arr[] = {
2067 { mod->syms, mod->num_syms },
2068 { mod->gpl_syms, mod->num_gpl_syms },
2069 { mod->gpl_future_syms, mod->num_gpl_future_syms },
2070 #ifdef CONFIG_UNUSED_SYMBOLS
2071 { mod->unused_syms, mod->num_unused_syms },
2072 { mod->unused_gpl_syms, mod->num_unused_gpl_syms },
2073 #endif
2076 for (i = 0; i < ARRAY_SIZE(arr); i++) {
2077 for (s = arr[i].sym; s < arr[i].sym + arr[i].num; s++) {
2078 if (find_symbol(s->name, &owner, NULL, true, false)) {
2079 pr_err("%s: exports duplicate symbol %s"
2080 " (owned by %s)\n",
2081 mod->name, s->name, module_name(owner));
2082 return -ENOEXEC;
2086 return 0;
2089 /* Change all symbols so that st_value encodes the pointer directly. */
2090 static int simplify_symbols(struct module *mod, const struct load_info *info)
2092 Elf_Shdr *symsec = &info->sechdrs[info->index.sym];
2093 Elf_Sym *sym = (void *)symsec->sh_addr;
2094 unsigned long secbase;
2095 unsigned int i;
2096 int ret = 0;
2097 const struct kernel_symbol *ksym;
2099 for (i = 1; i < symsec->sh_size / sizeof(Elf_Sym); i++) {
2100 const char *name = info->strtab + sym[i].st_name;
2102 switch (sym[i].st_shndx) {
2103 case SHN_COMMON:
2104 /* Ignore common symbols */
2105 if (!strncmp(name, "__gnu_lto", 9))
2106 break;
2108 /* We compiled with -fno-common. These are not
2109 supposed to happen. */
2110 pr_debug("Common symbol: %s\n", name);
2111 pr_warn("%s: please compile with -fno-common\n",
2112 mod->name);
2113 ret = -ENOEXEC;
2114 break;
2116 case SHN_ABS:
2117 /* Don't need to do anything */
2118 pr_debug("Absolute symbol: 0x%08lx\n",
2119 (long)sym[i].st_value);
2120 break;
2122 case SHN_UNDEF:
2123 ksym = resolve_symbol_wait(mod, info, name);
2124 /* Ok if resolved. */
2125 if (ksym && !IS_ERR(ksym)) {
2126 sym[i].st_value = ksym->value;
2127 break;
2130 /* Ok if weak. */
2131 if (!ksym && ELF_ST_BIND(sym[i].st_info) == STB_WEAK)
2132 break;
2134 pr_warn("%s: Unknown symbol %s (err %li)\n",
2135 mod->name, name, PTR_ERR(ksym));
2136 ret = PTR_ERR(ksym) ?: -ENOENT;
2137 break;
2139 default:
2140 /* Divert to percpu allocation if a percpu var. */
2141 if (sym[i].st_shndx == info->index.pcpu)
2142 secbase = (unsigned long)mod_percpu(mod);
2143 else
2144 secbase = info->sechdrs[sym[i].st_shndx].sh_addr;
2145 sym[i].st_value += secbase;
2146 break;
2150 return ret;
2153 static int apply_relocations(struct module *mod, const struct load_info *info)
2155 unsigned int i;
2156 int err = 0;
2158 /* Now do relocations. */
2159 for (i = 1; i < info->hdr->e_shnum; i++) {
2160 unsigned int infosec = info->sechdrs[i].sh_info;
2162 /* Not a valid relocation section? */
2163 if (infosec >= info->hdr->e_shnum)
2164 continue;
2166 /* Don't bother with non-allocated sections */
2167 if (!(info->sechdrs[infosec].sh_flags & SHF_ALLOC))
2168 continue;
2170 if (info->sechdrs[i].sh_type == SHT_REL)
2171 err = apply_relocate(info->sechdrs, info->strtab,
2172 info->index.sym, i, mod);
2173 else if (info->sechdrs[i].sh_type == SHT_RELA)
2174 err = apply_relocate_add(info->sechdrs, info->strtab,
2175 info->index.sym, i, mod);
2176 if (err < 0)
2177 break;
2179 return err;
2182 /* Additional bytes needed by arch in front of individual sections */
2183 unsigned int __weak arch_mod_section_prepend(struct module *mod,
2184 unsigned int section)
2186 /* default implementation just returns zero */
2187 return 0;
2190 /* Update size with this section: return offset. */
2191 static long get_offset(struct module *mod, unsigned int *size,
2192 Elf_Shdr *sechdr, unsigned int section)
2194 long ret;
2196 *size += arch_mod_section_prepend(mod, section);
2197 ret = ALIGN(*size, sechdr->sh_addralign ?: 1);
2198 *size = ret + sechdr->sh_size;
2199 return ret;
2202 /* Lay out the SHF_ALLOC sections in a way not dissimilar to how ld
2203 might -- code, read-only data, read-write data, small data. Tally
2204 sizes, and place the offsets into sh_entsize fields: high bit means it
2205 belongs in init. */
2206 static void layout_sections(struct module *mod, struct load_info *info)
2208 static unsigned long const masks[][2] = {
2209 /* NOTE: all executable code must be the first section
2210 * in this array; otherwise modify the text_size
2211 * finder in the two loops below */
2212 { SHF_EXECINSTR | SHF_ALLOC, ARCH_SHF_SMALL },
2213 { SHF_ALLOC, SHF_WRITE | ARCH_SHF_SMALL },
2214 { SHF_WRITE | SHF_ALLOC, ARCH_SHF_SMALL },
2215 { ARCH_SHF_SMALL | SHF_ALLOC, 0 }
2217 unsigned int m, i;
2219 for (i = 0; i < info->hdr->e_shnum; i++)
2220 info->sechdrs[i].sh_entsize = ~0UL;
2222 pr_debug("Core section allocation order:\n");
2223 for (m = 0; m < ARRAY_SIZE(masks); ++m) {
2224 for (i = 0; i < info->hdr->e_shnum; ++i) {
2225 Elf_Shdr *s = &info->sechdrs[i];
2226 const char *sname = info->secstrings + s->sh_name;
2228 if ((s->sh_flags & masks[m][0]) != masks[m][0]
2229 || (s->sh_flags & masks[m][1])
2230 || s->sh_entsize != ~0UL
2231 || strstarts(sname, ".init"))
2232 continue;
2233 s->sh_entsize = get_offset(mod, &mod->core_layout.size, s, i);
2234 pr_debug("\t%s\n", sname);
2236 switch (m) {
2237 case 0: /* executable */
2238 mod->core_layout.size = debug_align(mod->core_layout.size);
2239 mod->core_layout.text_size = mod->core_layout.size;
2240 break;
2241 case 1: /* RO: text and ro-data */
2242 mod->core_layout.size = debug_align(mod->core_layout.size);
2243 mod->core_layout.ro_size = mod->core_layout.size;
2244 break;
2245 case 3: /* whole core */
2246 mod->core_layout.size = debug_align(mod->core_layout.size);
2247 break;
2251 pr_debug("Init section allocation order:\n");
2252 for (m = 0; m < ARRAY_SIZE(masks); ++m) {
2253 for (i = 0; i < info->hdr->e_shnum; ++i) {
2254 Elf_Shdr *s = &info->sechdrs[i];
2255 const char *sname = info->secstrings + s->sh_name;
2257 if ((s->sh_flags & masks[m][0]) != masks[m][0]
2258 || (s->sh_flags & masks[m][1])
2259 || s->sh_entsize != ~0UL
2260 || !strstarts(sname, ".init"))
2261 continue;
2262 s->sh_entsize = (get_offset(mod, &mod->init_layout.size, s, i)
2263 | INIT_OFFSET_MASK);
2264 pr_debug("\t%s\n", sname);
2266 switch (m) {
2267 case 0: /* executable */
2268 mod->init_layout.size = debug_align(mod->init_layout.size);
2269 mod->init_layout.text_size = mod->init_layout.size;
2270 break;
2271 case 1: /* RO: text and ro-data */
2272 mod->init_layout.size = debug_align(mod->init_layout.size);
2273 mod->init_layout.ro_size = mod->init_layout.size;
2274 break;
2275 case 3: /* whole init */
2276 mod->init_layout.size = debug_align(mod->init_layout.size);
2277 break;
2282 static void set_license(struct module *mod, const char *license)
2284 if (!license)
2285 license = "unspecified";
2287 if (!license_is_gpl_compatible(license)) {
2288 if (!test_taint(TAINT_PROPRIETARY_MODULE))
2289 pr_warn("%s: module license '%s' taints kernel.\n",
2290 mod->name, license);
2291 add_taint_module(mod, TAINT_PROPRIETARY_MODULE,
2292 LOCKDEP_NOW_UNRELIABLE);
2296 /* Parse tag=value strings from .modinfo section */
2297 static char *next_string(char *string, unsigned long *secsize)
2299 /* Skip non-zero chars */
2300 while (string[0]) {
2301 string++;
2302 if ((*secsize)-- <= 1)
2303 return NULL;
2306 /* Skip any zero padding. */
2307 while (!string[0]) {
2308 string++;
2309 if ((*secsize)-- <= 1)
2310 return NULL;
2312 return string;
2315 static char *get_modinfo(struct load_info *info, const char *tag)
2317 char *p;
2318 unsigned int taglen = strlen(tag);
2319 Elf_Shdr *infosec = &info->sechdrs[info->index.info];
2320 unsigned long size = infosec->sh_size;
2322 for (p = (char *)infosec->sh_addr; p; p = next_string(p, &size)) {
2323 if (strncmp(p, tag, taglen) == 0 && p[taglen] == '=')
2324 return p + taglen + 1;
2326 return NULL;
2329 static void setup_modinfo(struct module *mod, struct load_info *info)
2331 struct module_attribute *attr;
2332 int i;
2334 for (i = 0; (attr = modinfo_attrs[i]); i++) {
2335 if (attr->setup)
2336 attr->setup(mod, get_modinfo(info, attr->attr.name));
2340 static void free_modinfo(struct module *mod)
2342 struct module_attribute *attr;
2343 int i;
2345 for (i = 0; (attr = modinfo_attrs[i]); i++) {
2346 if (attr->free)
2347 attr->free(mod);
2351 #ifdef CONFIG_KALLSYMS
2353 /* lookup symbol in given range of kernel_symbols */
2354 static const struct kernel_symbol *lookup_symbol(const char *name,
2355 const struct kernel_symbol *start,
2356 const struct kernel_symbol *stop)
2358 return bsearch(name, start, stop - start,
2359 sizeof(struct kernel_symbol), cmp_name);
2362 static int is_exported(const char *name, unsigned long value,
2363 const struct module *mod)
2365 const struct kernel_symbol *ks;
2366 if (!mod)
2367 ks = lookup_symbol(name, __start___ksymtab, __stop___ksymtab);
2368 else
2369 ks = lookup_symbol(name, mod->syms, mod->syms + mod->num_syms);
2370 return ks != NULL && ks->value == value;
2373 /* As per nm */
2374 static char elf_type(const Elf_Sym *sym, const struct load_info *info)
2376 const Elf_Shdr *sechdrs = info->sechdrs;
2378 if (ELF_ST_BIND(sym->st_info) == STB_WEAK) {
2379 if (ELF_ST_TYPE(sym->st_info) == STT_OBJECT)
2380 return 'v';
2381 else
2382 return 'w';
2384 if (sym->st_shndx == SHN_UNDEF)
2385 return 'U';
2386 if (sym->st_shndx == SHN_ABS || sym->st_shndx == info->index.pcpu)
2387 return 'a';
2388 if (sym->st_shndx >= SHN_LORESERVE)
2389 return '?';
2390 if (sechdrs[sym->st_shndx].sh_flags & SHF_EXECINSTR)
2391 return 't';
2392 if (sechdrs[sym->st_shndx].sh_flags & SHF_ALLOC
2393 && sechdrs[sym->st_shndx].sh_type != SHT_NOBITS) {
2394 if (!(sechdrs[sym->st_shndx].sh_flags & SHF_WRITE))
2395 return 'r';
2396 else if (sechdrs[sym->st_shndx].sh_flags & ARCH_SHF_SMALL)
2397 return 'g';
2398 else
2399 return 'd';
2401 if (sechdrs[sym->st_shndx].sh_type == SHT_NOBITS) {
2402 if (sechdrs[sym->st_shndx].sh_flags & ARCH_SHF_SMALL)
2403 return 's';
2404 else
2405 return 'b';
2407 if (strstarts(info->secstrings + sechdrs[sym->st_shndx].sh_name,
2408 ".debug")) {
2409 return 'n';
2411 return '?';
2414 static bool is_core_symbol(const Elf_Sym *src, const Elf_Shdr *sechdrs,
2415 unsigned int shnum, unsigned int pcpundx)
2417 const Elf_Shdr *sec;
2419 if (src->st_shndx == SHN_UNDEF
2420 || src->st_shndx >= shnum
2421 || !src->st_name)
2422 return false;
2424 #ifdef CONFIG_KALLSYMS_ALL
2425 if (src->st_shndx == pcpundx)
2426 return true;
2427 #endif
2429 sec = sechdrs + src->st_shndx;
2430 if (!(sec->sh_flags & SHF_ALLOC)
2431 #ifndef CONFIG_KALLSYMS_ALL
2432 || !(sec->sh_flags & SHF_EXECINSTR)
2433 #endif
2434 || (sec->sh_entsize & INIT_OFFSET_MASK))
2435 return false;
2437 return true;
2441 * We only allocate and copy the strings needed by the parts of symtab
2442 * we keep. This is simple, but has the effect of making multiple
2443 * copies of duplicates. We could be more sophisticated, see
2444 * linux-kernel thread starting with
2445 * <73defb5e4bca04a6431392cc341112b1@localhost>.
2447 static void layout_symtab(struct module *mod, struct load_info *info)
2449 Elf_Shdr *symsect = info->sechdrs + info->index.sym;
2450 Elf_Shdr *strsect = info->sechdrs + info->index.str;
2451 const Elf_Sym *src;
2452 unsigned int i, nsrc, ndst, strtab_size = 0;
2454 /* Put symbol section at end of init part of module. */
2455 symsect->sh_flags |= SHF_ALLOC;
2456 symsect->sh_entsize = get_offset(mod, &mod->init_layout.size, symsect,
2457 info->index.sym) | INIT_OFFSET_MASK;
2458 pr_debug("\t%s\n", info->secstrings + symsect->sh_name);
2460 src = (void *)info->hdr + symsect->sh_offset;
2461 nsrc = symsect->sh_size / sizeof(*src);
2463 /* Compute total space required for the core symbols' strtab. */
2464 for (ndst = i = 0; i < nsrc; i++) {
2465 if (i == 0 ||
2466 is_core_symbol(src+i, info->sechdrs, info->hdr->e_shnum,
2467 info->index.pcpu)) {
2468 strtab_size += strlen(&info->strtab[src[i].st_name])+1;
2469 ndst++;
2473 /* Append room for core symbols at end of core part. */
2474 info->symoffs = ALIGN(mod->core_layout.size, symsect->sh_addralign ?: 1);
2475 info->stroffs = mod->core_layout.size = info->symoffs + ndst * sizeof(Elf_Sym);
2476 mod->core_layout.size += strtab_size;
2477 mod->core_layout.size = debug_align(mod->core_layout.size);
2479 /* Put string table section at end of init part of module. */
2480 strsect->sh_flags |= SHF_ALLOC;
2481 strsect->sh_entsize = get_offset(mod, &mod->init_layout.size, strsect,
2482 info->index.str) | INIT_OFFSET_MASK;
2483 mod->init_layout.size = debug_align(mod->init_layout.size);
2484 pr_debug("\t%s\n", info->secstrings + strsect->sh_name);
2487 static void add_kallsyms(struct module *mod, const struct load_info *info)
2489 unsigned int i, ndst;
2490 const Elf_Sym *src;
2491 Elf_Sym *dst;
2492 char *s;
2493 Elf_Shdr *symsec = &info->sechdrs[info->index.sym];
2495 mod->symtab = (void *)symsec->sh_addr;
2496 mod->num_symtab = symsec->sh_size / sizeof(Elf_Sym);
2497 /* Make sure we get permanent strtab: don't use info->strtab. */
2498 mod->strtab = (void *)info->sechdrs[info->index.str].sh_addr;
2500 /* Set types up while we still have access to sections. */
2501 for (i = 0; i < mod->num_symtab; i++)
2502 mod->symtab[i].st_info = elf_type(&mod->symtab[i], info);
2504 mod->core_symtab = dst = mod->core_layout.base + info->symoffs;
2505 mod->core_strtab = s = mod->core_layout.base + info->stroffs;
2506 src = mod->symtab;
2507 for (ndst = i = 0; i < mod->num_symtab; i++) {
2508 if (i == 0 ||
2509 is_core_symbol(src+i, info->sechdrs, info->hdr->e_shnum,
2510 info->index.pcpu)) {
2511 dst[ndst] = src[i];
2512 dst[ndst++].st_name = s - mod->core_strtab;
2513 s += strlcpy(s, &mod->strtab[src[i].st_name],
2514 KSYM_NAME_LEN) + 1;
2517 mod->core_num_syms = ndst;
2519 #else
2520 static inline void layout_symtab(struct module *mod, struct load_info *info)
2524 static void add_kallsyms(struct module *mod, const struct load_info *info)
2527 #endif /* CONFIG_KALLSYMS */
2529 static void dynamic_debug_setup(struct _ddebug *debug, unsigned int num)
2531 if (!debug)
2532 return;
2533 #ifdef CONFIG_DYNAMIC_DEBUG
2534 if (ddebug_add_module(debug, num, debug->modname))
2535 pr_err("dynamic debug error adding module: %s\n",
2536 debug->modname);
2537 #endif
2540 static void dynamic_debug_remove(struct _ddebug *debug)
2542 if (debug)
2543 ddebug_remove_module(debug->modname);
2546 void * __weak module_alloc(unsigned long size)
2548 return vmalloc_exec(size);
2551 #ifdef CONFIG_DEBUG_KMEMLEAK
2552 static void kmemleak_load_module(const struct module *mod,
2553 const struct load_info *info)
2555 unsigned int i;
2557 /* only scan the sections containing data */
2558 kmemleak_scan_area(mod, sizeof(struct module), GFP_KERNEL);
2560 for (i = 1; i < info->hdr->e_shnum; i++) {
2561 /* Scan all writable sections that's not executable */
2562 if (!(info->sechdrs[i].sh_flags & SHF_ALLOC) ||
2563 !(info->sechdrs[i].sh_flags & SHF_WRITE) ||
2564 (info->sechdrs[i].sh_flags & SHF_EXECINSTR))
2565 continue;
2567 kmemleak_scan_area((void *)info->sechdrs[i].sh_addr,
2568 info->sechdrs[i].sh_size, GFP_KERNEL);
2571 #else
2572 static inline void kmemleak_load_module(const struct module *mod,
2573 const struct load_info *info)
2576 #endif
2578 #ifdef CONFIG_MODULE_SIG
2579 static int module_sig_check(struct load_info *info)
2581 int err = -ENOKEY;
2582 const unsigned long markerlen = sizeof(MODULE_SIG_STRING) - 1;
2583 const void *mod = info->hdr;
2585 if (info->len > markerlen &&
2586 memcmp(mod + info->len - markerlen, MODULE_SIG_STRING, markerlen) == 0) {
2587 /* We truncate the module to discard the signature */
2588 info->len -= markerlen;
2589 err = mod_verify_sig(mod, &info->len);
2592 if (!err) {
2593 info->sig_ok = true;
2594 return 0;
2597 /* Not having a signature is only an error if we're strict. */
2598 if (err == -ENOKEY && !sig_enforce)
2599 err = 0;
2601 return err;
2603 #else /* !CONFIG_MODULE_SIG */
2604 static int module_sig_check(struct load_info *info)
2606 return 0;
2608 #endif /* !CONFIG_MODULE_SIG */
2610 /* Sanity checks against invalid binaries, wrong arch, weird elf version. */
2611 static int elf_header_check(struct load_info *info)
2613 if (info->len < sizeof(*(info->hdr)))
2614 return -ENOEXEC;
2616 if (memcmp(info->hdr->e_ident, ELFMAG, SELFMAG) != 0
2617 || info->hdr->e_type != ET_REL
2618 || !elf_check_arch(info->hdr)
2619 || info->hdr->e_shentsize != sizeof(Elf_Shdr))
2620 return -ENOEXEC;
2622 if (info->hdr->e_shoff >= info->len
2623 || (info->hdr->e_shnum * sizeof(Elf_Shdr) >
2624 info->len - info->hdr->e_shoff))
2625 return -ENOEXEC;
2627 return 0;
2630 #define COPY_CHUNK_SIZE (16*PAGE_SIZE)
2632 static int copy_chunked_from_user(void *dst, const void __user *usrc, unsigned long len)
2634 do {
2635 unsigned long n = min(len, COPY_CHUNK_SIZE);
2637 if (copy_from_user(dst, usrc, n) != 0)
2638 return -EFAULT;
2639 cond_resched();
2640 dst += n;
2641 usrc += n;
2642 len -= n;
2643 } while (len);
2644 return 0;
2647 /* Sets info->hdr and info->len. */
2648 static int copy_module_from_user(const void __user *umod, unsigned long len,
2649 struct load_info *info)
2651 int err;
2653 info->len = len;
2654 if (info->len < sizeof(*(info->hdr)))
2655 return -ENOEXEC;
2657 err = security_kernel_module_from_file(NULL);
2658 if (err)
2659 return err;
2661 /* Suck in entire file: we'll want most of it. */
2662 info->hdr = __vmalloc(info->len,
2663 GFP_KERNEL | __GFP_HIGHMEM | __GFP_NOWARN, PAGE_KERNEL);
2664 if (!info->hdr)
2665 return -ENOMEM;
2667 if (copy_chunked_from_user(info->hdr, umod, info->len) != 0) {
2668 vfree(info->hdr);
2669 return -EFAULT;
2672 return 0;
2675 /* Sets info->hdr and info->len. */
2676 static int copy_module_from_fd(int fd, struct load_info *info)
2678 struct fd f = fdget(fd);
2679 int err;
2680 struct kstat stat;
2681 loff_t pos;
2682 ssize_t bytes = 0;
2684 if (!f.file)
2685 return -ENOEXEC;
2687 err = security_kernel_module_from_file(f.file);
2688 if (err)
2689 goto out;
2691 err = vfs_getattr(&f.file->f_path, &stat);
2692 if (err)
2693 goto out;
2695 if (stat.size > INT_MAX) {
2696 err = -EFBIG;
2697 goto out;
2700 /* Don't hand 0 to vmalloc, it whines. */
2701 if (stat.size == 0) {
2702 err = -EINVAL;
2703 goto out;
2706 info->hdr = vmalloc(stat.size);
2707 if (!info->hdr) {
2708 err = -ENOMEM;
2709 goto out;
2712 pos = 0;
2713 while (pos < stat.size) {
2714 bytes = kernel_read(f.file, pos, (char *)(info->hdr) + pos,
2715 stat.size - pos);
2716 if (bytes < 0) {
2717 vfree(info->hdr);
2718 err = bytes;
2719 goto out;
2721 if (bytes == 0)
2722 break;
2723 pos += bytes;
2725 info->len = pos;
2727 out:
2728 fdput(f);
2729 return err;
2732 static void free_copy(struct load_info *info)
2734 vfree(info->hdr);
2737 static int rewrite_section_headers(struct load_info *info, int flags)
2739 unsigned int i;
2741 /* This should always be true, but let's be sure. */
2742 info->sechdrs[0].sh_addr = 0;
2744 for (i = 1; i < info->hdr->e_shnum; i++) {
2745 Elf_Shdr *shdr = &info->sechdrs[i];
2746 if (shdr->sh_type != SHT_NOBITS
2747 && info->len < shdr->sh_offset + shdr->sh_size) {
2748 pr_err("Module len %lu truncated\n", info->len);
2749 return -ENOEXEC;
2752 /* Mark all sections sh_addr with their address in the
2753 temporary image. */
2754 shdr->sh_addr = (size_t)info->hdr + shdr->sh_offset;
2756 #ifndef CONFIG_MODULE_UNLOAD
2757 /* Don't load .exit sections */
2758 if (strstarts(info->secstrings+shdr->sh_name, ".exit"))
2759 shdr->sh_flags &= ~(unsigned long)SHF_ALLOC;
2760 #endif
2763 /* Track but don't keep modinfo and version sections. */
2764 if (flags & MODULE_INIT_IGNORE_MODVERSIONS)
2765 info->index.vers = 0; /* Pretend no __versions section! */
2766 else
2767 info->index.vers = find_sec(info, "__versions");
2768 info->index.info = find_sec(info, ".modinfo");
2769 info->sechdrs[info->index.info].sh_flags &= ~(unsigned long)SHF_ALLOC;
2770 info->sechdrs[info->index.vers].sh_flags &= ~(unsigned long)SHF_ALLOC;
2771 return 0;
2775 * Set up our basic convenience variables (pointers to section headers,
2776 * search for module section index etc), and do some basic section
2777 * verification.
2779 * Return the temporary module pointer (we'll replace it with the final
2780 * one when we move the module sections around).
2782 static struct module *setup_load_info(struct load_info *info, int flags)
2784 unsigned int i;
2785 int err;
2786 struct module *mod;
2788 /* Set up the convenience variables */
2789 info->sechdrs = (void *)info->hdr + info->hdr->e_shoff;
2790 info->secstrings = (void *)info->hdr
2791 + info->sechdrs[info->hdr->e_shstrndx].sh_offset;
2793 err = rewrite_section_headers(info, flags);
2794 if (err)
2795 return ERR_PTR(err);
2797 /* Find internal symbols and strings. */
2798 for (i = 1; i < info->hdr->e_shnum; i++) {
2799 if (info->sechdrs[i].sh_type == SHT_SYMTAB) {
2800 info->index.sym = i;
2801 info->index.str = info->sechdrs[i].sh_link;
2802 info->strtab = (char *)info->hdr
2803 + info->sechdrs[info->index.str].sh_offset;
2804 break;
2808 info->index.mod = find_sec(info, ".gnu.linkonce.this_module");
2809 if (!info->index.mod) {
2810 pr_warn("No module found in object\n");
2811 return ERR_PTR(-ENOEXEC);
2813 /* This is temporary: point mod into copy of data. */
2814 mod = (void *)info->sechdrs[info->index.mod].sh_addr;
2816 if (info->index.sym == 0) {
2817 pr_warn("%s: module has no symbols (stripped?)\n", mod->name);
2818 return ERR_PTR(-ENOEXEC);
2821 info->index.pcpu = find_pcpusec(info);
2823 /* Check module struct version now, before we try to use module. */
2824 if (!check_modstruct_version(info->sechdrs, info->index.vers, mod))
2825 return ERR_PTR(-ENOEXEC);
2827 return mod;
2830 static int check_modinfo(struct module *mod, struct load_info *info, int flags)
2832 const char *modmagic = get_modinfo(info, "vermagic");
2833 int err;
2835 if (flags & MODULE_INIT_IGNORE_VERMAGIC)
2836 modmagic = NULL;
2838 /* This is allowed: modprobe --force will invalidate it. */
2839 if (!modmagic) {
2840 err = try_to_force_load(mod, "bad vermagic");
2841 if (err)
2842 return err;
2843 } else if (!same_magic(modmagic, vermagic, info->index.vers)) {
2844 pr_err("%s: version magic '%s' should be '%s'\n",
2845 mod->name, modmagic, vermagic);
2846 return -ENOEXEC;
2849 if (!get_modinfo(info, "intree"))
2850 add_taint_module(mod, TAINT_OOT_MODULE, LOCKDEP_STILL_OK);
2852 if (get_modinfo(info, "staging")) {
2853 add_taint_module(mod, TAINT_CRAP, LOCKDEP_STILL_OK);
2854 pr_warn("%s: module is from the staging directory, the quality "
2855 "is unknown, you have been warned.\n", mod->name);
2858 /* Set up license info based on the info section */
2859 set_license(mod, get_modinfo(info, "license"));
2861 return 0;
2864 static int find_module_sections(struct module *mod, struct load_info *info)
2866 mod->kp = section_objs(info, "__param",
2867 sizeof(*mod->kp), &mod->num_kp);
2868 mod->syms = section_objs(info, "__ksymtab",
2869 sizeof(*mod->syms), &mod->num_syms);
2870 mod->crcs = section_addr(info, "__kcrctab");
2871 mod->gpl_syms = section_objs(info, "__ksymtab_gpl",
2872 sizeof(*mod->gpl_syms),
2873 &mod->num_gpl_syms);
2874 mod->gpl_crcs = section_addr(info, "__kcrctab_gpl");
2875 mod->gpl_future_syms = section_objs(info,
2876 "__ksymtab_gpl_future",
2877 sizeof(*mod->gpl_future_syms),
2878 &mod->num_gpl_future_syms);
2879 mod->gpl_future_crcs = section_addr(info, "__kcrctab_gpl_future");
2881 #ifdef CONFIG_UNUSED_SYMBOLS
2882 mod->unused_syms = section_objs(info, "__ksymtab_unused",
2883 sizeof(*mod->unused_syms),
2884 &mod->num_unused_syms);
2885 mod->unused_crcs = section_addr(info, "__kcrctab_unused");
2886 mod->unused_gpl_syms = section_objs(info, "__ksymtab_unused_gpl",
2887 sizeof(*mod->unused_gpl_syms),
2888 &mod->num_unused_gpl_syms);
2889 mod->unused_gpl_crcs = section_addr(info, "__kcrctab_unused_gpl");
2890 #endif
2891 #ifdef CONFIG_CONSTRUCTORS
2892 mod->ctors = section_objs(info, ".ctors",
2893 sizeof(*mod->ctors), &mod->num_ctors);
2894 if (!mod->ctors)
2895 mod->ctors = section_objs(info, ".init_array",
2896 sizeof(*mod->ctors), &mod->num_ctors);
2897 else if (find_sec(info, ".init_array")) {
2899 * This shouldn't happen with same compiler and binutils
2900 * building all parts of the module.
2902 pr_warn("%s: has both .ctors and .init_array.\n",
2903 mod->name);
2904 return -EINVAL;
2906 #endif
2908 #ifdef CONFIG_TRACEPOINTS
2909 mod->tracepoints_ptrs = section_objs(info, "__tracepoints_ptrs",
2910 sizeof(*mod->tracepoints_ptrs),
2911 &mod->num_tracepoints);
2912 #endif
2913 #ifdef HAVE_JUMP_LABEL
2914 mod->jump_entries = section_objs(info, "__jump_table",
2915 sizeof(*mod->jump_entries),
2916 &mod->num_jump_entries);
2917 #endif
2918 #ifdef CONFIG_EVENT_TRACING
2919 mod->trace_events = section_objs(info, "_ftrace_events",
2920 sizeof(*mod->trace_events),
2921 &mod->num_trace_events);
2922 mod->trace_enums = section_objs(info, "_ftrace_enum_map",
2923 sizeof(*mod->trace_enums),
2924 &mod->num_trace_enums);
2925 #endif
2926 #ifdef CONFIG_TRACING
2927 mod->trace_bprintk_fmt_start = section_objs(info, "__trace_printk_fmt",
2928 sizeof(*mod->trace_bprintk_fmt_start),
2929 &mod->num_trace_bprintk_fmt);
2930 #endif
2931 #ifdef CONFIG_FTRACE_MCOUNT_RECORD
2932 /* sechdrs[0].sh_size is always zero */
2933 mod->ftrace_callsites = section_objs(info, "__mcount_loc",
2934 sizeof(*mod->ftrace_callsites),
2935 &mod->num_ftrace_callsites);
2936 #endif
2938 mod->extable = section_objs(info, "__ex_table",
2939 sizeof(*mod->extable), &mod->num_exentries);
2941 if (section_addr(info, "__obsparm"))
2942 pr_warn("%s: Ignoring obsolete parameters\n", mod->name);
2944 info->debug = section_objs(info, "__verbose",
2945 sizeof(*info->debug), &info->num_debug);
2947 return 0;
2950 static int move_module(struct module *mod, struct load_info *info)
2952 int i;
2953 void *ptr;
2955 /* Do the allocs. */
2956 ptr = module_alloc(mod->core_layout.size);
2958 * The pointer to this block is stored in the module structure
2959 * which is inside the block. Just mark it as not being a
2960 * leak.
2962 kmemleak_not_leak(ptr);
2963 if (!ptr)
2964 return -ENOMEM;
2966 memset(ptr, 0, mod->core_layout.size);
2967 mod->core_layout.base = ptr;
2969 if (mod->init_layout.size) {
2970 ptr = module_alloc(mod->init_layout.size);
2972 * The pointer to this block is stored in the module structure
2973 * which is inside the block. This block doesn't need to be
2974 * scanned as it contains data and code that will be freed
2975 * after the module is initialized.
2977 kmemleak_ignore(ptr);
2978 if (!ptr) {
2979 module_memfree(mod->core_layout.base);
2980 return -ENOMEM;
2982 memset(ptr, 0, mod->init_layout.size);
2983 mod->init_layout.base = ptr;
2984 } else
2985 mod->init_layout.base = NULL;
2987 /* Transfer each section which specifies SHF_ALLOC */
2988 pr_debug("final section addresses:\n");
2989 for (i = 0; i < info->hdr->e_shnum; i++) {
2990 void *dest;
2991 Elf_Shdr *shdr = &info->sechdrs[i];
2993 if (!(shdr->sh_flags & SHF_ALLOC))
2994 continue;
2996 if (shdr->sh_entsize & INIT_OFFSET_MASK)
2997 dest = mod->init_layout.base
2998 + (shdr->sh_entsize & ~INIT_OFFSET_MASK);
2999 else
3000 dest = mod->core_layout.base + shdr->sh_entsize;
3002 if (shdr->sh_type != SHT_NOBITS)
3003 memcpy(dest, (void *)shdr->sh_addr, shdr->sh_size);
3004 /* Update sh_addr to point to copy in image. */
3005 shdr->sh_addr = (unsigned long)dest;
3006 pr_debug("\t0x%lx %s\n",
3007 (long)shdr->sh_addr, info->secstrings + shdr->sh_name);
3010 return 0;
3013 static int check_module_license_and_versions(struct module *mod)
3016 * ndiswrapper is under GPL by itself, but loads proprietary modules.
3017 * Don't use add_taint_module(), as it would prevent ndiswrapper from
3018 * using GPL-only symbols it needs.
3020 if (strcmp(mod->name, "ndiswrapper") == 0)
3021 add_taint(TAINT_PROPRIETARY_MODULE, LOCKDEP_NOW_UNRELIABLE);
3023 /* driverloader was caught wrongly pretending to be under GPL */
3024 if (strcmp(mod->name, "driverloader") == 0)
3025 add_taint_module(mod, TAINT_PROPRIETARY_MODULE,
3026 LOCKDEP_NOW_UNRELIABLE);
3028 /* lve claims to be GPL but upstream won't provide source */
3029 if (strcmp(mod->name, "lve") == 0)
3030 add_taint_module(mod, TAINT_PROPRIETARY_MODULE,
3031 LOCKDEP_NOW_UNRELIABLE);
3033 #ifdef CONFIG_MODVERSIONS
3034 if ((mod->num_syms && !mod->crcs)
3035 || (mod->num_gpl_syms && !mod->gpl_crcs)
3036 || (mod->num_gpl_future_syms && !mod->gpl_future_crcs)
3037 #ifdef CONFIG_UNUSED_SYMBOLS
3038 || (mod->num_unused_syms && !mod->unused_crcs)
3039 || (mod->num_unused_gpl_syms && !mod->unused_gpl_crcs)
3040 #endif
3042 return try_to_force_load(mod,
3043 "no versions for exported symbols");
3045 #endif
3046 return 0;
3049 static void flush_module_icache(const struct module *mod)
3051 mm_segment_t old_fs;
3053 /* flush the icache in correct context */
3054 old_fs = get_fs();
3055 set_fs(KERNEL_DS);
3058 * Flush the instruction cache, since we've played with text.
3059 * Do it before processing of module parameters, so the module
3060 * can provide parameter accessor functions of its own.
3062 if (mod->init_layout.base)
3063 flush_icache_range((unsigned long)mod->init_layout.base,
3064 (unsigned long)mod->init_layout.base
3065 + mod->init_layout.size);
3066 flush_icache_range((unsigned long)mod->core_layout.base,
3067 (unsigned long)mod->core_layout.base + mod->core_layout.size);
3069 set_fs(old_fs);
3072 int __weak module_frob_arch_sections(Elf_Ehdr *hdr,
3073 Elf_Shdr *sechdrs,
3074 char *secstrings,
3075 struct module *mod)
3077 return 0;
3080 static struct module *layout_and_allocate(struct load_info *info, int flags)
3082 /* Module within temporary copy. */
3083 struct module *mod;
3084 int err;
3086 mod = setup_load_info(info, flags);
3087 if (IS_ERR(mod))
3088 return mod;
3090 err = check_modinfo(mod, info, flags);
3091 if (err)
3092 return ERR_PTR(err);
3094 /* Allow arches to frob section contents and sizes. */
3095 err = module_frob_arch_sections(info->hdr, info->sechdrs,
3096 info->secstrings, mod);
3097 if (err < 0)
3098 return ERR_PTR(err);
3100 /* We will do a special allocation for per-cpu sections later. */
3101 info->sechdrs[info->index.pcpu].sh_flags &= ~(unsigned long)SHF_ALLOC;
3103 /* Determine total sizes, and put offsets in sh_entsize. For now
3104 this is done generically; there doesn't appear to be any
3105 special cases for the architectures. */
3106 layout_sections(mod, info);
3107 layout_symtab(mod, info);
3109 /* Allocate and move to the final place */
3110 err = move_module(mod, info);
3111 if (err)
3112 return ERR_PTR(err);
3114 /* Module has been copied to its final place now: return it. */
3115 mod = (void *)info->sechdrs[info->index.mod].sh_addr;
3116 kmemleak_load_module(mod, info);
3117 return mod;
3120 /* mod is no longer valid after this! */
3121 static void module_deallocate(struct module *mod, struct load_info *info)
3123 percpu_modfree(mod);
3124 module_arch_freeing_init(mod);
3125 module_memfree(mod->init_layout.base);
3126 module_memfree(mod->core_layout.base);
3129 int __weak module_finalize(const Elf_Ehdr *hdr,
3130 const Elf_Shdr *sechdrs,
3131 struct module *me)
3133 return 0;
3136 static int post_relocation(struct module *mod, const struct load_info *info)
3138 /* Sort exception table now relocations are done. */
3139 sort_extable(mod->extable, mod->extable + mod->num_exentries);
3141 /* Copy relocated percpu area over. */
3142 percpu_modcopy(mod, (void *)info->sechdrs[info->index.pcpu].sh_addr,
3143 info->sechdrs[info->index.pcpu].sh_size);
3145 /* Setup kallsyms-specific fields. */
3146 add_kallsyms(mod, info);
3148 /* Arch-specific module finalizing. */
3149 return module_finalize(info->hdr, info->sechdrs, mod);
3152 /* Is this module of this name done loading? No locks held. */
3153 static bool finished_loading(const char *name)
3155 struct module *mod;
3156 bool ret;
3159 * The module_mutex should not be a heavily contended lock;
3160 * if we get the occasional sleep here, we'll go an extra iteration
3161 * in the wait_event_interruptible(), which is harmless.
3163 sched_annotate_sleep();
3164 mutex_lock(&module_mutex);
3165 mod = find_module_all(name, strlen(name), true);
3166 ret = !mod || mod->state == MODULE_STATE_LIVE
3167 || mod->state == MODULE_STATE_GOING;
3168 mutex_unlock(&module_mutex);
3170 return ret;
3173 /* Call module constructors. */
3174 static void do_mod_ctors(struct module *mod)
3176 #ifdef CONFIG_CONSTRUCTORS
3177 unsigned long i;
3179 for (i = 0; i < mod->num_ctors; i++)
3180 mod->ctors[i]();
3181 #endif
3184 /* For freeing module_init on success, in case kallsyms traversing */
3185 struct mod_initfree {
3186 struct rcu_head rcu;
3187 void *module_init;
3190 static void do_free_init(struct rcu_head *head)
3192 struct mod_initfree *m = container_of(head, struct mod_initfree, rcu);
3193 module_memfree(m->module_init);
3194 kfree(m);
3198 * This is where the real work happens.
3200 * Keep it uninlined to provide a reliable breakpoint target, e.g. for the gdb
3201 * helper command 'lx-symbols'.
3203 static noinline int do_init_module(struct module *mod)
3205 int ret = 0;
3206 struct mod_initfree *freeinit;
3208 freeinit = kmalloc(sizeof(*freeinit), GFP_KERNEL);
3209 if (!freeinit) {
3210 ret = -ENOMEM;
3211 goto fail;
3213 freeinit->module_init = mod->init_layout.base;
3216 * We want to find out whether @mod uses async during init. Clear
3217 * PF_USED_ASYNC. async_schedule*() will set it.
3219 current->flags &= ~PF_USED_ASYNC;
3221 do_mod_ctors(mod);
3222 /* Start the module */
3223 if (mod->init != NULL)
3224 ret = do_one_initcall(mod->init);
3225 if (ret < 0) {
3226 goto fail_free_freeinit;
3228 if (ret > 0) {
3229 pr_warn("%s: '%s'->init suspiciously returned %d, it should "
3230 "follow 0/-E convention\n"
3231 "%s: loading module anyway...\n",
3232 __func__, mod->name, ret, __func__);
3233 dump_stack();
3236 /* Now it's a first class citizen! */
3237 mod->state = MODULE_STATE_LIVE;
3238 blocking_notifier_call_chain(&module_notify_list,
3239 MODULE_STATE_LIVE, mod);
3242 * We need to finish all async code before the module init sequence
3243 * is done. This has potential to deadlock. For example, a newly
3244 * detected block device can trigger request_module() of the
3245 * default iosched from async probing task. Once userland helper
3246 * reaches here, async_synchronize_full() will wait on the async
3247 * task waiting on request_module() and deadlock.
3249 * This deadlock is avoided by perfomring async_synchronize_full()
3250 * iff module init queued any async jobs. This isn't a full
3251 * solution as it will deadlock the same if module loading from
3252 * async jobs nests more than once; however, due to the various
3253 * constraints, this hack seems to be the best option for now.
3254 * Please refer to the following thread for details.
3256 * http://thread.gmane.org/gmane.linux.kernel/1420814
3258 if (!mod->async_probe_requested && (current->flags & PF_USED_ASYNC))
3259 async_synchronize_full();
3261 mutex_lock(&module_mutex);
3262 /* Drop initial reference. */
3263 module_put(mod);
3264 trim_init_extable(mod);
3265 #ifdef CONFIG_KALLSYMS
3266 mod->num_symtab = mod->core_num_syms;
3267 mod->symtab = mod->core_symtab;
3268 mod->strtab = mod->core_strtab;
3269 #endif
3270 mod_tree_remove_init(mod);
3271 disable_ro_nx(&mod->init_layout);
3272 module_arch_freeing_init(mod);
3273 mod->init_layout.base = NULL;
3274 mod->init_layout.size = 0;
3275 mod->init_layout.ro_size = 0;
3276 mod->init_layout.text_size = 0;
3278 * We want to free module_init, but be aware that kallsyms may be
3279 * walking this with preempt disabled. In all the failure paths, we
3280 * call synchronize_sched(), but we don't want to slow down the success
3281 * path, so use actual RCU here.
3283 call_rcu_sched(&freeinit->rcu, do_free_init);
3284 mutex_unlock(&module_mutex);
3285 wake_up_all(&module_wq);
3287 return 0;
3289 fail_free_freeinit:
3290 kfree(freeinit);
3291 fail:
3292 /* Try to protect us from buggy refcounters. */
3293 mod->state = MODULE_STATE_GOING;
3294 synchronize_sched();
3295 module_put(mod);
3296 blocking_notifier_call_chain(&module_notify_list,
3297 MODULE_STATE_GOING, mod);
3298 free_module(mod);
3299 wake_up_all(&module_wq);
3300 return ret;
3303 static int may_init_module(void)
3305 if (!capable(CAP_SYS_MODULE) || modules_disabled)
3306 return -EPERM;
3308 return 0;
3312 * We try to place it in the list now to make sure it's unique before
3313 * we dedicate too many resources. In particular, temporary percpu
3314 * memory exhaustion.
3316 static int add_unformed_module(struct module *mod)
3318 int err;
3319 struct module *old;
3321 mod->state = MODULE_STATE_UNFORMED;
3323 again:
3324 mutex_lock(&module_mutex);
3325 old = find_module_all(mod->name, strlen(mod->name), true);
3326 if (old != NULL) {
3327 if (old->state == MODULE_STATE_COMING
3328 || old->state == MODULE_STATE_UNFORMED) {
3329 /* Wait in case it fails to load. */
3330 mutex_unlock(&module_mutex);
3331 err = wait_event_interruptible(module_wq,
3332 finished_loading(mod->name));
3333 if (err)
3334 goto out_unlocked;
3335 goto again;
3337 err = -EEXIST;
3338 goto out;
3340 mod_update_bounds(mod);
3341 list_add_rcu(&mod->list, &modules);
3342 mod_tree_insert(mod);
3343 err = 0;
3345 out:
3346 mutex_unlock(&module_mutex);
3347 out_unlocked:
3348 return err;
3351 static int complete_formation(struct module *mod, struct load_info *info)
3353 int err;
3355 mutex_lock(&module_mutex);
3357 /* Find duplicate symbols (must be called under lock). */
3358 err = verify_export_symbols(mod);
3359 if (err < 0)
3360 goto out;
3362 /* This relies on module_mutex for list integrity. */
3363 module_bug_finalize(info->hdr, info->sechdrs, mod);
3365 /* Set RO and NX regions */
3366 module_enable_ro(mod);
3367 module_enable_nx(mod);
3369 /* Mark state as coming so strong_try_module_get() ignores us,
3370 * but kallsyms etc. can see us. */
3371 mod->state = MODULE_STATE_COMING;
3372 mutex_unlock(&module_mutex);
3374 blocking_notifier_call_chain(&module_notify_list,
3375 MODULE_STATE_COMING, mod);
3376 return 0;
3378 out:
3379 mutex_unlock(&module_mutex);
3380 return err;
3383 static int unknown_module_param_cb(char *param, char *val, const char *modname,
3384 void *arg)
3386 struct module *mod = arg;
3387 int ret;
3389 if (strcmp(param, "async_probe") == 0) {
3390 mod->async_probe_requested = true;
3391 return 0;
3394 /* Check for magic 'dyndbg' arg */
3395 ret = ddebug_dyndbg_module_param_cb(param, val, modname);
3396 if (ret != 0)
3397 pr_warn("%s: unknown parameter '%s' ignored\n", modname, param);
3398 return 0;
3401 /* Allocate and load the module: note that size of section 0 is always
3402 zero, and we rely on this for optional sections. */
3403 static int load_module(struct load_info *info, const char __user *uargs,
3404 int flags)
3406 struct module *mod;
3407 long err;
3408 char *after_dashes;
3410 err = module_sig_check(info);
3411 if (err)
3412 goto free_copy;
3414 err = elf_header_check(info);
3415 if (err)
3416 goto free_copy;
3418 /* Figure out module layout, and allocate all the memory. */
3419 mod = layout_and_allocate(info, flags);
3420 if (IS_ERR(mod)) {
3421 err = PTR_ERR(mod);
3422 goto free_copy;
3425 /* Reserve our place in the list. */
3426 err = add_unformed_module(mod);
3427 if (err)
3428 goto free_module;
3430 #ifdef CONFIG_MODULE_SIG
3431 mod->sig_ok = info->sig_ok;
3432 if (!mod->sig_ok) {
3433 pr_notice_once("%s: module verification failed: signature "
3434 "and/or required key missing - tainting "
3435 "kernel\n", mod->name);
3436 add_taint_module(mod, TAINT_UNSIGNED_MODULE, LOCKDEP_STILL_OK);
3438 #endif
3440 /* To avoid stressing percpu allocator, do this once we're unique. */
3441 err = percpu_modalloc(mod, info);
3442 if (err)
3443 goto unlink_mod;
3445 /* Now module is in final location, initialize linked lists, etc. */
3446 err = module_unload_init(mod);
3447 if (err)
3448 goto unlink_mod;
3450 init_param_lock(mod);
3452 /* Now we've got everything in the final locations, we can
3453 * find optional sections. */
3454 err = find_module_sections(mod, info);
3455 if (err)
3456 goto free_unload;
3458 err = check_module_license_and_versions(mod);
3459 if (err)
3460 goto free_unload;
3462 /* Set up MODINFO_ATTR fields */
3463 setup_modinfo(mod, info);
3465 /* Fix up syms, so that st_value is a pointer to location. */
3466 err = simplify_symbols(mod, info);
3467 if (err < 0)
3468 goto free_modinfo;
3470 err = apply_relocations(mod, info);
3471 if (err < 0)
3472 goto free_modinfo;
3474 err = post_relocation(mod, info);
3475 if (err < 0)
3476 goto free_modinfo;
3478 flush_module_icache(mod);
3480 /* Now copy in args */
3481 mod->args = strndup_user(uargs, ~0UL >> 1);
3482 if (IS_ERR(mod->args)) {
3483 err = PTR_ERR(mod->args);
3484 goto free_arch_cleanup;
3487 dynamic_debug_setup(info->debug, info->num_debug);
3489 /* Ftrace init must be called in the MODULE_STATE_UNFORMED state */
3490 ftrace_module_init(mod);
3492 /* Finally it's fully formed, ready to start executing. */
3493 err = complete_formation(mod, info);
3494 if (err)
3495 goto ddebug_cleanup;
3497 /* Module is ready to execute: parsing args may do that. */
3498 after_dashes = parse_args(mod->name, mod->args, mod->kp, mod->num_kp,
3499 -32768, 32767, NULL,
3500 unknown_module_param_cb);
3501 if (IS_ERR(after_dashes)) {
3502 err = PTR_ERR(after_dashes);
3503 goto bug_cleanup;
3504 } else if (after_dashes) {
3505 pr_warn("%s: parameters '%s' after `--' ignored\n",
3506 mod->name, after_dashes);
3509 /* Link in to syfs. */
3510 err = mod_sysfs_setup(mod, info, mod->kp, mod->num_kp);
3511 if (err < 0)
3512 goto bug_cleanup;
3514 /* Get rid of temporary copy. */
3515 free_copy(info);
3517 /* Done! */
3518 trace_module_load(mod);
3520 return do_init_module(mod);
3522 bug_cleanup:
3523 /* module_bug_cleanup needs module_mutex protection */
3524 mutex_lock(&module_mutex);
3525 module_bug_cleanup(mod);
3526 mutex_unlock(&module_mutex);
3528 blocking_notifier_call_chain(&module_notify_list,
3529 MODULE_STATE_GOING, mod);
3531 /* we can't deallocate the module until we clear memory protection */
3532 module_disable_ro(mod);
3533 module_disable_nx(mod);
3535 ddebug_cleanup:
3536 dynamic_debug_remove(info->debug);
3537 synchronize_sched();
3538 kfree(mod->args);
3539 free_arch_cleanup:
3540 module_arch_cleanup(mod);
3541 free_modinfo:
3542 free_modinfo(mod);
3543 free_unload:
3544 module_unload_free(mod);
3545 unlink_mod:
3546 mutex_lock(&module_mutex);
3547 /* Unlink carefully: kallsyms could be walking list. */
3548 list_del_rcu(&mod->list);
3549 mod_tree_remove(mod);
3550 wake_up_all(&module_wq);
3551 /* Wait for RCU-sched synchronizing before releasing mod->list. */
3552 synchronize_sched();
3553 mutex_unlock(&module_mutex);
3554 free_module:
3556 * Ftrace needs to clean up what it initialized.
3557 * This does nothing if ftrace_module_init() wasn't called,
3558 * but it must be called outside of module_mutex.
3560 ftrace_release_mod(mod);
3561 /* Free lock-classes; relies on the preceding sync_rcu() */
3562 lockdep_free_key_range(mod->core_layout.base, mod->core_layout.size);
3564 module_deallocate(mod, info);
3565 free_copy:
3566 free_copy(info);
3567 return err;
3570 SYSCALL_DEFINE3(init_module, void __user *, umod,
3571 unsigned long, len, const char __user *, uargs)
3573 int err;
3574 struct load_info info = { };
3576 err = may_init_module();
3577 if (err)
3578 return err;
3580 pr_debug("init_module: umod=%p, len=%lu, uargs=%p\n",
3581 umod, len, uargs);
3583 err = copy_module_from_user(umod, len, &info);
3584 if (err)
3585 return err;
3587 return load_module(&info, uargs, 0);
3590 SYSCALL_DEFINE3(finit_module, int, fd, const char __user *, uargs, int, flags)
3592 int err;
3593 struct load_info info = { };
3595 err = may_init_module();
3596 if (err)
3597 return err;
3599 pr_debug("finit_module: fd=%d, uargs=%p, flags=%i\n", fd, uargs, flags);
3601 if (flags & ~(MODULE_INIT_IGNORE_MODVERSIONS
3602 |MODULE_INIT_IGNORE_VERMAGIC))
3603 return -EINVAL;
3605 err = copy_module_from_fd(fd, &info);
3606 if (err)
3607 return err;
3609 return load_module(&info, uargs, flags);
3612 static inline int within(unsigned long addr, void *start, unsigned long size)
3614 return ((void *)addr >= start && (void *)addr < start + size);
3617 #ifdef CONFIG_KALLSYMS
3619 * This ignores the intensely annoying "mapping symbols" found
3620 * in ARM ELF files: $a, $t and $d.
3622 static inline int is_arm_mapping_symbol(const char *str)
3624 if (str[0] == '.' && str[1] == 'L')
3625 return true;
3626 return str[0] == '$' && strchr("axtd", str[1])
3627 && (str[2] == '\0' || str[2] == '.');
3630 static const char *get_ksymbol(struct module *mod,
3631 unsigned long addr,
3632 unsigned long *size,
3633 unsigned long *offset)
3635 unsigned int i, best = 0;
3636 unsigned long nextval;
3638 /* At worse, next value is at end of module */
3639 if (within_module_init(addr, mod))
3640 nextval = (unsigned long)mod->init_layout.base+mod->init_layout.text_size;
3641 else
3642 nextval = (unsigned long)mod->core_layout.base+mod->core_layout.text_size;
3644 /* Scan for closest preceding symbol, and next symbol. (ELF
3645 starts real symbols at 1). */
3646 for (i = 1; i < mod->num_symtab; i++) {
3647 if (mod->symtab[i].st_shndx == SHN_UNDEF)
3648 continue;
3650 /* We ignore unnamed symbols: they're uninformative
3651 * and inserted at a whim. */
3652 if (mod->symtab[i].st_value <= addr
3653 && mod->symtab[i].st_value > mod->symtab[best].st_value
3654 && *(mod->strtab + mod->symtab[i].st_name) != '\0'
3655 && !is_arm_mapping_symbol(mod->strtab + mod->symtab[i].st_name))
3656 best = i;
3657 if (mod->symtab[i].st_value > addr
3658 && mod->symtab[i].st_value < nextval
3659 && *(mod->strtab + mod->symtab[i].st_name) != '\0'
3660 && !is_arm_mapping_symbol(mod->strtab + mod->symtab[i].st_name))
3661 nextval = mod->symtab[i].st_value;
3664 if (!best)
3665 return NULL;
3667 if (size)
3668 *size = nextval - mod->symtab[best].st_value;
3669 if (offset)
3670 *offset = addr - mod->symtab[best].st_value;
3671 return mod->strtab + mod->symtab[best].st_name;
3674 /* For kallsyms to ask for address resolution. NULL means not found. Careful
3675 * not to lock to avoid deadlock on oopses, simply disable preemption. */
3676 const char *module_address_lookup(unsigned long addr,
3677 unsigned long *size,
3678 unsigned long *offset,
3679 char **modname,
3680 char *namebuf)
3682 const char *ret = NULL;
3683 struct module *mod;
3685 preempt_disable();
3686 mod = __module_address(addr);
3687 if (mod) {
3688 if (modname)
3689 *modname = mod->name;
3690 ret = get_ksymbol(mod, addr, size, offset);
3692 /* Make a copy in here where it's safe */
3693 if (ret) {
3694 strncpy(namebuf, ret, KSYM_NAME_LEN - 1);
3695 ret = namebuf;
3697 preempt_enable();
3699 return ret;
3702 int lookup_module_symbol_name(unsigned long addr, char *symname)
3704 struct module *mod;
3706 preempt_disable();
3707 list_for_each_entry_rcu(mod, &modules, list) {
3708 if (mod->state == MODULE_STATE_UNFORMED)
3709 continue;
3710 if (within_module(addr, mod)) {
3711 const char *sym;
3713 sym = get_ksymbol(mod, addr, NULL, NULL);
3714 if (!sym)
3715 goto out;
3716 strlcpy(symname, sym, KSYM_NAME_LEN);
3717 preempt_enable();
3718 return 0;
3721 out:
3722 preempt_enable();
3723 return -ERANGE;
3726 int lookup_module_symbol_attrs(unsigned long addr, unsigned long *size,
3727 unsigned long *offset, char *modname, char *name)
3729 struct module *mod;
3731 preempt_disable();
3732 list_for_each_entry_rcu(mod, &modules, list) {
3733 if (mod->state == MODULE_STATE_UNFORMED)
3734 continue;
3735 if (within_module(addr, mod)) {
3736 const char *sym;
3738 sym = get_ksymbol(mod, addr, size, offset);
3739 if (!sym)
3740 goto out;
3741 if (modname)
3742 strlcpy(modname, mod->name, MODULE_NAME_LEN);
3743 if (name)
3744 strlcpy(name, sym, KSYM_NAME_LEN);
3745 preempt_enable();
3746 return 0;
3749 out:
3750 preempt_enable();
3751 return -ERANGE;
3754 int module_get_kallsym(unsigned int symnum, unsigned long *value, char *type,
3755 char *name, char *module_name, int *exported)
3757 struct module *mod;
3759 preempt_disable();
3760 list_for_each_entry_rcu(mod, &modules, list) {
3761 if (mod->state == MODULE_STATE_UNFORMED)
3762 continue;
3763 if (symnum < mod->num_symtab) {
3764 *value = mod->symtab[symnum].st_value;
3765 *type = mod->symtab[symnum].st_info;
3766 strlcpy(name, mod->strtab + mod->symtab[symnum].st_name,
3767 KSYM_NAME_LEN);
3768 strlcpy(module_name, mod->name, MODULE_NAME_LEN);
3769 *exported = is_exported(name, *value, mod);
3770 preempt_enable();
3771 return 0;
3773 symnum -= mod->num_symtab;
3775 preempt_enable();
3776 return -ERANGE;
3779 static unsigned long mod_find_symname(struct module *mod, const char *name)
3781 unsigned int i;
3783 for (i = 0; i < mod->num_symtab; i++)
3784 if (strcmp(name, mod->strtab+mod->symtab[i].st_name) == 0 &&
3785 mod->symtab[i].st_info != 'U')
3786 return mod->symtab[i].st_value;
3787 return 0;
3790 /* Look for this name: can be of form module:name. */
3791 unsigned long module_kallsyms_lookup_name(const char *name)
3793 struct module *mod;
3794 char *colon;
3795 unsigned long ret = 0;
3797 /* Don't lock: we're in enough trouble already. */
3798 preempt_disable();
3799 if ((colon = strchr(name, ':')) != NULL) {
3800 if ((mod = find_module_all(name, colon - name, false)) != NULL)
3801 ret = mod_find_symname(mod, colon+1);
3802 } else {
3803 list_for_each_entry_rcu(mod, &modules, list) {
3804 if (mod->state == MODULE_STATE_UNFORMED)
3805 continue;
3806 if ((ret = mod_find_symname(mod, name)) != 0)
3807 break;
3810 preempt_enable();
3811 return ret;
3814 int module_kallsyms_on_each_symbol(int (*fn)(void *, const char *,
3815 struct module *, unsigned long),
3816 void *data)
3818 struct module *mod;
3819 unsigned int i;
3820 int ret;
3822 module_assert_mutex();
3824 list_for_each_entry(mod, &modules, list) {
3825 if (mod->state == MODULE_STATE_UNFORMED)
3826 continue;
3827 for (i = 0; i < mod->num_symtab; i++) {
3828 ret = fn(data, mod->strtab + mod->symtab[i].st_name,
3829 mod, mod->symtab[i].st_value);
3830 if (ret != 0)
3831 return ret;
3834 return 0;
3836 #endif /* CONFIG_KALLSYMS */
3838 static char *module_flags(struct module *mod, char *buf)
3840 int bx = 0;
3842 BUG_ON(mod->state == MODULE_STATE_UNFORMED);
3843 if (mod->taints ||
3844 mod->state == MODULE_STATE_GOING ||
3845 mod->state == MODULE_STATE_COMING) {
3846 buf[bx++] = '(';
3847 bx += module_flags_taint(mod, buf + bx);
3848 /* Show a - for module-is-being-unloaded */
3849 if (mod->state == MODULE_STATE_GOING)
3850 buf[bx++] = '-';
3851 /* Show a + for module-is-being-loaded */
3852 if (mod->state == MODULE_STATE_COMING)
3853 buf[bx++] = '+';
3854 buf[bx++] = ')';
3856 buf[bx] = '\0';
3858 return buf;
3861 #ifdef CONFIG_PROC_FS
3862 /* Called by the /proc file system to return a list of modules. */
3863 static void *m_start(struct seq_file *m, loff_t *pos)
3865 mutex_lock(&module_mutex);
3866 return seq_list_start(&modules, *pos);
3869 static void *m_next(struct seq_file *m, void *p, loff_t *pos)
3871 return seq_list_next(p, &modules, pos);
3874 static void m_stop(struct seq_file *m, void *p)
3876 mutex_unlock(&module_mutex);
3879 static int m_show(struct seq_file *m, void *p)
3881 struct module *mod = list_entry(p, struct module, list);
3882 char buf[8];
3884 /* We always ignore unformed modules. */
3885 if (mod->state == MODULE_STATE_UNFORMED)
3886 return 0;
3888 seq_printf(m, "%s %u",
3889 mod->name, mod->init_layout.size + mod->core_layout.size);
3890 print_unload_info(m, mod);
3892 /* Informative for users. */
3893 seq_printf(m, " %s",
3894 mod->state == MODULE_STATE_GOING ? "Unloading" :
3895 mod->state == MODULE_STATE_COMING ? "Loading" :
3896 "Live");
3897 /* Used by oprofile and other similar tools. */
3898 seq_printf(m, " 0x%pK", mod->core_layout.base);
3900 /* Taints info */
3901 if (mod->taints)
3902 seq_printf(m, " %s", module_flags(mod, buf));
3904 seq_puts(m, "\n");
3905 return 0;
3908 /* Format: modulename size refcount deps address
3910 Where refcount is a number or -, and deps is a comma-separated list
3911 of depends or -.
3913 static const struct seq_operations modules_op = {
3914 .start = m_start,
3915 .next = m_next,
3916 .stop = m_stop,
3917 .show = m_show
3920 static int modules_open(struct inode *inode, struct file *file)
3922 return seq_open(file, &modules_op);
3925 static const struct file_operations proc_modules_operations = {
3926 .open = modules_open,
3927 .read = seq_read,
3928 .llseek = seq_lseek,
3929 .release = seq_release,
3932 static int __init proc_modules_init(void)
3934 proc_create("modules", 0, NULL, &proc_modules_operations);
3935 return 0;
3937 module_init(proc_modules_init);
3938 #endif
3940 /* Given an address, look for it in the module exception tables. */
3941 const struct exception_table_entry *search_module_extables(unsigned long addr)
3943 const struct exception_table_entry *e = NULL;
3944 struct module *mod;
3946 preempt_disable();
3947 list_for_each_entry_rcu(mod, &modules, list) {
3948 if (mod->state == MODULE_STATE_UNFORMED)
3949 continue;
3950 if (mod->num_exentries == 0)
3951 continue;
3953 e = search_extable(mod->extable,
3954 mod->extable + mod->num_exentries - 1,
3955 addr);
3956 if (e)
3957 break;
3959 preempt_enable();
3961 /* Now, if we found one, we are running inside it now, hence
3962 we cannot unload the module, hence no refcnt needed. */
3963 return e;
3967 * is_module_address - is this address inside a module?
3968 * @addr: the address to check.
3970 * See is_module_text_address() if you simply want to see if the address
3971 * is code (not data).
3973 bool is_module_address(unsigned long addr)
3975 bool ret;
3977 preempt_disable();
3978 ret = __module_address(addr) != NULL;
3979 preempt_enable();
3981 return ret;
3985 * __module_address - get the module which contains an address.
3986 * @addr: the address.
3988 * Must be called with preempt disabled or module mutex held so that
3989 * module doesn't get freed during this.
3991 struct module *__module_address(unsigned long addr)
3993 struct module *mod;
3995 if (addr < module_addr_min || addr > module_addr_max)
3996 return NULL;
3998 module_assert_mutex_or_preempt();
4000 mod = mod_find(addr);
4001 if (mod) {
4002 BUG_ON(!within_module(addr, mod));
4003 if (mod->state == MODULE_STATE_UNFORMED)
4004 mod = NULL;
4006 return mod;
4008 EXPORT_SYMBOL_GPL(__module_address);
4011 * is_module_text_address - is this address inside module code?
4012 * @addr: the address to check.
4014 * See is_module_address() if you simply want to see if the address is
4015 * anywhere in a module. See kernel_text_address() for testing if an
4016 * address corresponds to kernel or module code.
4018 bool is_module_text_address(unsigned long addr)
4020 bool ret;
4022 preempt_disable();
4023 ret = __module_text_address(addr) != NULL;
4024 preempt_enable();
4026 return ret;
4030 * __module_text_address - get the module whose code contains an address.
4031 * @addr: the address.
4033 * Must be called with preempt disabled or module mutex held so that
4034 * module doesn't get freed during this.
4036 struct module *__module_text_address(unsigned long addr)
4038 struct module *mod = __module_address(addr);
4039 if (mod) {
4040 /* Make sure it's within the text section. */
4041 if (!within(addr, mod->init_layout.base, mod->init_layout.text_size)
4042 && !within(addr, mod->core_layout.base, mod->core_layout.text_size))
4043 mod = NULL;
4045 return mod;
4047 EXPORT_SYMBOL_GPL(__module_text_address);
4049 /* Don't grab lock, we're oopsing. */
4050 void print_modules(void)
4052 struct module *mod;
4053 char buf[8];
4055 printk(KERN_DEFAULT "Modules linked in:");
4056 /* Most callers should already have preempt disabled, but make sure */
4057 preempt_disable();
4058 list_for_each_entry_rcu(mod, &modules, list) {
4059 if (mod->state == MODULE_STATE_UNFORMED)
4060 continue;
4061 pr_cont(" %s%s", mod->name, module_flags(mod, buf));
4063 preempt_enable();
4064 if (last_unloaded_module[0])
4065 pr_cont(" [last unloaded: %s]", last_unloaded_module);
4066 pr_cont("\n");
4069 #ifdef CONFIG_MODVERSIONS
4070 /* Generate the signature for all relevant module structures here.
4071 * If these change, we don't want to try to parse the module. */
4072 void module_layout(struct module *mod,
4073 struct modversion_info *ver,
4074 struct kernel_param *kp,
4075 struct kernel_symbol *ks,
4076 struct tracepoint * const *tp)
4079 EXPORT_SYMBOL(module_layout);
4080 #endif