mtip32xx: fix error handling in mtip_init()
[zen-stable.git] / kernel / module.c
blob3d56b6f5fb5eba58409f1ab1c7e9a92fa8655fda
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/ftrace_event.h>
22 #include <linux/init.h>
23 #include <linux/kallsyms.h>
24 #include <linux/fs.h>
25 #include <linux/sysfs.h>
26 #include <linux/kernel.h>
27 #include <linux/slab.h>
28 #include <linux/vmalloc.h>
29 #include <linux/elf.h>
30 #include <linux/proc_fs.h>
31 #include <linux/seq_file.h>
32 #include <linux/syscalls.h>
33 #include <linux/fcntl.h>
34 #include <linux/rcupdate.h>
35 #include <linux/capability.h>
36 #include <linux/cpu.h>
37 #include <linux/moduleparam.h>
38 #include <linux/errno.h>
39 #include <linux/err.h>
40 #include <linux/vermagic.h>
41 #include <linux/notifier.h>
42 #include <linux/sched.h>
43 #include <linux/stop_machine.h>
44 #include <linux/device.h>
45 #include <linux/string.h>
46 #include <linux/mutex.h>
47 #include <linux/rculist.h>
48 #include <asm/uaccess.h>
49 #include <asm/cacheflush.h>
50 #include <asm/mmu_context.h>
51 #include <linux/license.h>
52 #include <asm/sections.h>
53 #include <linux/tracepoint.h>
54 #include <linux/ftrace.h>
55 #include <linux/async.h>
56 #include <linux/percpu.h>
57 #include <linux/kmemleak.h>
58 #include <linux/jump_label.h>
59 #include <linux/pfn.h>
60 #include <linux/bsearch.h>
62 #define CREATE_TRACE_POINTS
63 #include <trace/events/module.h>
65 #ifndef ARCH_SHF_SMALL
66 #define ARCH_SHF_SMALL 0
67 #endif
70 * Modules' sections will be aligned on page boundaries
71 * to ensure complete separation of code and data, but
72 * only when CONFIG_DEBUG_SET_MODULE_RONX=y
74 #ifdef CONFIG_DEBUG_SET_MODULE_RONX
75 # define debug_align(X) ALIGN(X, PAGE_SIZE)
76 #else
77 # define debug_align(X) (X)
78 #endif
81 * Given BASE and SIZE this macro calculates the number of pages the
82 * memory regions occupies
84 #define MOD_NUMBER_OF_PAGES(BASE, SIZE) (((SIZE) > 0) ? \
85 (PFN_DOWN((unsigned long)(BASE) + (SIZE) - 1) - \
86 PFN_DOWN((unsigned long)BASE) + 1) \
87 : (0UL))
89 /* If this is set, the section belongs in the init part of the module */
90 #define INIT_OFFSET_MASK (1UL << (BITS_PER_LONG-1))
93 * Mutex protects:
94 * 1) List of modules (also safely readable with preempt_disable),
95 * 2) module_use links,
96 * 3) module_addr_min/module_addr_max.
97 * (delete uses stop_machine/add uses RCU list operations). */
98 DEFINE_MUTEX(module_mutex);
99 EXPORT_SYMBOL_GPL(module_mutex);
100 static LIST_HEAD(modules);
101 #ifdef CONFIG_KGDB_KDB
102 struct list_head *kdb_modules = &modules; /* kdb needs the list of modules */
103 #endif /* CONFIG_KGDB_KDB */
106 /* Block module loading/unloading? */
107 int modules_disabled = 0;
109 /* Waiting for a module to finish initializing? */
110 static DECLARE_WAIT_QUEUE_HEAD(module_wq);
112 static BLOCKING_NOTIFIER_HEAD(module_notify_list);
114 /* Bounds of module allocation, for speeding __module_address.
115 * Protected by module_mutex. */
116 static unsigned long module_addr_min = -1UL, module_addr_max = 0;
118 int register_module_notifier(struct notifier_block * nb)
120 return blocking_notifier_chain_register(&module_notify_list, nb);
122 EXPORT_SYMBOL(register_module_notifier);
124 int unregister_module_notifier(struct notifier_block * nb)
126 return blocking_notifier_chain_unregister(&module_notify_list, nb);
128 EXPORT_SYMBOL(unregister_module_notifier);
130 struct load_info {
131 Elf_Ehdr *hdr;
132 unsigned long len;
133 Elf_Shdr *sechdrs;
134 char *secstrings, *strtab;
135 unsigned long symoffs, stroffs;
136 struct _ddebug *debug;
137 unsigned int num_debug;
138 struct {
139 unsigned int sym, str, mod, vers, info, pcpu;
140 } index;
143 /* We require a truly strong try_module_get(): 0 means failure due to
144 ongoing or failed initialization etc. */
145 static inline int strong_try_module_get(struct module *mod)
147 if (mod && mod->state == MODULE_STATE_COMING)
148 return -EBUSY;
149 if (try_module_get(mod))
150 return 0;
151 else
152 return -ENOENT;
155 static inline void add_taint_module(struct module *mod, unsigned flag)
157 add_taint(flag);
158 mod->taints |= (1U << flag);
162 * A thread that wants to hold a reference to a module only while it
163 * is running can call this to safely exit. nfsd and lockd use this.
165 void __module_put_and_exit(struct module *mod, long code)
167 module_put(mod);
168 do_exit(code);
170 EXPORT_SYMBOL(__module_put_and_exit);
172 /* Find a module section: 0 means not found. */
173 static unsigned int find_sec(const struct load_info *info, const char *name)
175 unsigned int i;
177 for (i = 1; i < info->hdr->e_shnum; i++) {
178 Elf_Shdr *shdr = &info->sechdrs[i];
179 /* Alloc bit cleared means "ignore it." */
180 if ((shdr->sh_flags & SHF_ALLOC)
181 && strcmp(info->secstrings + shdr->sh_name, name) == 0)
182 return i;
184 return 0;
187 /* Find a module section, or NULL. */
188 static void *section_addr(const struct load_info *info, const char *name)
190 /* Section 0 has sh_addr 0. */
191 return (void *)info->sechdrs[find_sec(info, name)].sh_addr;
194 /* Find a module section, or NULL. Fill in number of "objects" in section. */
195 static void *section_objs(const struct load_info *info,
196 const char *name,
197 size_t object_size,
198 unsigned int *num)
200 unsigned int sec = find_sec(info, name);
202 /* Section 0 has sh_addr 0 and sh_size 0. */
203 *num = info->sechdrs[sec].sh_size / object_size;
204 return (void *)info->sechdrs[sec].sh_addr;
207 /* Provided by the linker */
208 extern const struct kernel_symbol __start___ksymtab[];
209 extern const struct kernel_symbol __stop___ksymtab[];
210 extern const struct kernel_symbol __start___ksymtab_gpl[];
211 extern const struct kernel_symbol __stop___ksymtab_gpl[];
212 extern const struct kernel_symbol __start___ksymtab_gpl_future[];
213 extern const struct kernel_symbol __stop___ksymtab_gpl_future[];
214 extern const unsigned long __start___kcrctab[];
215 extern const unsigned long __start___kcrctab_gpl[];
216 extern const unsigned long __start___kcrctab_gpl_future[];
217 #ifdef CONFIG_UNUSED_SYMBOLS
218 extern const struct kernel_symbol __start___ksymtab_unused[];
219 extern const struct kernel_symbol __stop___ksymtab_unused[];
220 extern const struct kernel_symbol __start___ksymtab_unused_gpl[];
221 extern const struct kernel_symbol __stop___ksymtab_unused_gpl[];
222 extern const unsigned long __start___kcrctab_unused[];
223 extern const unsigned long __start___kcrctab_unused_gpl[];
224 #endif
226 #ifndef CONFIG_MODVERSIONS
227 #define symversion(base, idx) NULL
228 #else
229 #define symversion(base, idx) ((base != NULL) ? ((base) + (idx)) : NULL)
230 #endif
232 static bool each_symbol_in_section(const struct symsearch *arr,
233 unsigned int arrsize,
234 struct module *owner,
235 bool (*fn)(const struct symsearch *syms,
236 struct module *owner,
237 void *data),
238 void *data)
240 unsigned int j;
242 for (j = 0; j < arrsize; j++) {
243 if (fn(&arr[j], owner, data))
244 return true;
247 return false;
250 /* Returns true as soon as fn returns true, otherwise false. */
251 bool each_symbol_section(bool (*fn)(const struct symsearch *arr,
252 struct module *owner,
253 void *data),
254 void *data)
256 struct module *mod;
257 static const struct symsearch arr[] = {
258 { __start___ksymtab, __stop___ksymtab, __start___kcrctab,
259 NOT_GPL_ONLY, false },
260 { __start___ksymtab_gpl, __stop___ksymtab_gpl,
261 __start___kcrctab_gpl,
262 GPL_ONLY, false },
263 { __start___ksymtab_gpl_future, __stop___ksymtab_gpl_future,
264 __start___kcrctab_gpl_future,
265 WILL_BE_GPL_ONLY, false },
266 #ifdef CONFIG_UNUSED_SYMBOLS
267 { __start___ksymtab_unused, __stop___ksymtab_unused,
268 __start___kcrctab_unused,
269 NOT_GPL_ONLY, true },
270 { __start___ksymtab_unused_gpl, __stop___ksymtab_unused_gpl,
271 __start___kcrctab_unused_gpl,
272 GPL_ONLY, true },
273 #endif
276 if (each_symbol_in_section(arr, ARRAY_SIZE(arr), NULL, fn, data))
277 return true;
279 list_for_each_entry_rcu(mod, &modules, list) {
280 struct symsearch arr[] = {
281 { mod->syms, mod->syms + mod->num_syms, mod->crcs,
282 NOT_GPL_ONLY, false },
283 { mod->gpl_syms, mod->gpl_syms + mod->num_gpl_syms,
284 mod->gpl_crcs,
285 GPL_ONLY, false },
286 { mod->gpl_future_syms,
287 mod->gpl_future_syms + mod->num_gpl_future_syms,
288 mod->gpl_future_crcs,
289 WILL_BE_GPL_ONLY, false },
290 #ifdef CONFIG_UNUSED_SYMBOLS
291 { mod->unused_syms,
292 mod->unused_syms + mod->num_unused_syms,
293 mod->unused_crcs,
294 NOT_GPL_ONLY, true },
295 { mod->unused_gpl_syms,
296 mod->unused_gpl_syms + mod->num_unused_gpl_syms,
297 mod->unused_gpl_crcs,
298 GPL_ONLY, true },
299 #endif
302 if (each_symbol_in_section(arr, ARRAY_SIZE(arr), mod, fn, data))
303 return true;
305 return false;
307 EXPORT_SYMBOL_GPL(each_symbol_section);
309 struct find_symbol_arg {
310 /* Input */
311 const char *name;
312 bool gplok;
313 bool warn;
315 /* Output */
316 struct module *owner;
317 const unsigned long *crc;
318 const struct kernel_symbol *sym;
321 static bool check_symbol(const struct symsearch *syms,
322 struct module *owner,
323 unsigned int symnum, void *data)
325 struct find_symbol_arg *fsa = data;
327 if (!fsa->gplok) {
328 if (syms->licence == GPL_ONLY)
329 return false;
330 if (syms->licence == WILL_BE_GPL_ONLY && fsa->warn) {
331 printk(KERN_WARNING "Symbol %s is being used "
332 "by a non-GPL module, which will not "
333 "be allowed in the future\n", fsa->name);
334 printk(KERN_WARNING "Please see the file "
335 "Documentation/feature-removal-schedule.txt "
336 "in the kernel source tree for more details.\n");
340 #ifdef CONFIG_UNUSED_SYMBOLS
341 if (syms->unused && fsa->warn) {
342 printk(KERN_WARNING "Symbol %s is marked as UNUSED, "
343 "however this module is using it.\n", fsa->name);
344 printk(KERN_WARNING
345 "This symbol will go away in the future.\n");
346 printk(KERN_WARNING
347 "Please evalute if this is the right api to use and if "
348 "it really is, submit a report the linux kernel "
349 "mailinglist together with submitting your code for "
350 "inclusion.\n");
352 #endif
354 fsa->owner = owner;
355 fsa->crc = symversion(syms->crcs, symnum);
356 fsa->sym = &syms->start[symnum];
357 return true;
360 static int cmp_name(const void *va, const void *vb)
362 const char *a;
363 const struct kernel_symbol *b;
364 a = va; b = vb;
365 return strcmp(a, b->name);
368 static bool find_symbol_in_section(const struct symsearch *syms,
369 struct module *owner,
370 void *data)
372 struct find_symbol_arg *fsa = data;
373 struct kernel_symbol *sym;
375 sym = bsearch(fsa->name, syms->start, syms->stop - syms->start,
376 sizeof(struct kernel_symbol), cmp_name);
378 if (sym != NULL && check_symbol(syms, owner, sym - syms->start, data))
379 return true;
381 return false;
384 /* Find a symbol and return it, along with, (optional) crc and
385 * (optional) module which owns it. Needs preempt disabled or module_mutex. */
386 const struct kernel_symbol *find_symbol(const char *name,
387 struct module **owner,
388 const unsigned long **crc,
389 bool gplok,
390 bool warn)
392 struct find_symbol_arg fsa;
394 fsa.name = name;
395 fsa.gplok = gplok;
396 fsa.warn = warn;
398 if (each_symbol_section(find_symbol_in_section, &fsa)) {
399 if (owner)
400 *owner = fsa.owner;
401 if (crc)
402 *crc = fsa.crc;
403 return fsa.sym;
406 pr_debug("Failed to find symbol %s\n", name);
407 return NULL;
409 EXPORT_SYMBOL_GPL(find_symbol);
411 /* Search for module by name: must hold module_mutex. */
412 struct module *find_module(const char *name)
414 struct module *mod;
416 list_for_each_entry(mod, &modules, list) {
417 if (strcmp(mod->name, name) == 0)
418 return mod;
420 return NULL;
422 EXPORT_SYMBOL_GPL(find_module);
424 #ifdef CONFIG_SMP
426 static inline void __percpu *mod_percpu(struct module *mod)
428 return mod->percpu;
431 static int percpu_modalloc(struct module *mod,
432 unsigned long size, unsigned long align)
434 if (align > PAGE_SIZE) {
435 printk(KERN_WARNING "%s: per-cpu alignment %li > %li\n",
436 mod->name, align, PAGE_SIZE);
437 align = PAGE_SIZE;
440 mod->percpu = __alloc_reserved_percpu(size, align);
441 if (!mod->percpu) {
442 printk(KERN_WARNING
443 "%s: Could not allocate %lu bytes percpu data\n",
444 mod->name, size);
445 return -ENOMEM;
447 mod->percpu_size = size;
448 return 0;
451 static void percpu_modfree(struct module *mod)
453 free_percpu(mod->percpu);
456 static unsigned int find_pcpusec(struct load_info *info)
458 return find_sec(info, ".data..percpu");
461 static void percpu_modcopy(struct module *mod,
462 const void *from, unsigned long size)
464 int cpu;
466 for_each_possible_cpu(cpu)
467 memcpy(per_cpu_ptr(mod->percpu, cpu), from, size);
471 * is_module_percpu_address - test whether address is from module static percpu
472 * @addr: address to test
474 * Test whether @addr belongs to module static percpu area.
476 * RETURNS:
477 * %true if @addr is from module static percpu area
479 bool is_module_percpu_address(unsigned long addr)
481 struct module *mod;
482 unsigned int cpu;
484 preempt_disable();
486 list_for_each_entry_rcu(mod, &modules, list) {
487 if (!mod->percpu_size)
488 continue;
489 for_each_possible_cpu(cpu) {
490 void *start = per_cpu_ptr(mod->percpu, cpu);
492 if ((void *)addr >= start &&
493 (void *)addr < start + mod->percpu_size) {
494 preempt_enable();
495 return true;
500 preempt_enable();
501 return false;
504 #else /* ... !CONFIG_SMP */
506 static inline void __percpu *mod_percpu(struct module *mod)
508 return NULL;
510 static inline int percpu_modalloc(struct module *mod,
511 unsigned long size, unsigned long align)
513 return -ENOMEM;
515 static inline void percpu_modfree(struct module *mod)
518 static unsigned int find_pcpusec(struct load_info *info)
520 return 0;
522 static inline void percpu_modcopy(struct module *mod,
523 const void *from, unsigned long size)
525 /* pcpusec should be 0, and size of that section should be 0. */
526 BUG_ON(size != 0);
528 bool is_module_percpu_address(unsigned long addr)
530 return false;
533 #endif /* CONFIG_SMP */
535 #define MODINFO_ATTR(field) \
536 static void setup_modinfo_##field(struct module *mod, const char *s) \
538 mod->field = kstrdup(s, GFP_KERNEL); \
540 static ssize_t show_modinfo_##field(struct module_attribute *mattr, \
541 struct module_kobject *mk, char *buffer) \
543 return sprintf(buffer, "%s\n", mk->mod->field); \
545 static int modinfo_##field##_exists(struct module *mod) \
547 return mod->field != NULL; \
549 static void free_modinfo_##field(struct module *mod) \
551 kfree(mod->field); \
552 mod->field = NULL; \
554 static struct module_attribute modinfo_##field = { \
555 .attr = { .name = __stringify(field), .mode = 0444 }, \
556 .show = show_modinfo_##field, \
557 .setup = setup_modinfo_##field, \
558 .test = modinfo_##field##_exists, \
559 .free = free_modinfo_##field, \
562 MODINFO_ATTR(version);
563 MODINFO_ATTR(srcversion);
565 static char last_unloaded_module[MODULE_NAME_LEN+1];
567 #ifdef CONFIG_MODULE_UNLOAD
569 EXPORT_TRACEPOINT_SYMBOL(module_get);
571 /* Init the unload section of the module. */
572 static int module_unload_init(struct module *mod)
574 mod->refptr = alloc_percpu(struct module_ref);
575 if (!mod->refptr)
576 return -ENOMEM;
578 INIT_LIST_HEAD(&mod->source_list);
579 INIT_LIST_HEAD(&mod->target_list);
581 /* Hold reference count during initialization. */
582 __this_cpu_write(mod->refptr->incs, 1);
583 /* Backwards compatibility macros put refcount during init. */
584 mod->waiter = current;
586 return 0;
589 /* Does a already use b? */
590 static int already_uses(struct module *a, struct module *b)
592 struct module_use *use;
594 list_for_each_entry(use, &b->source_list, source_list) {
595 if (use->source == a) {
596 pr_debug("%s uses %s!\n", a->name, b->name);
597 return 1;
600 pr_debug("%s does not use %s!\n", a->name, b->name);
601 return 0;
605 * Module a uses b
606 * - we add 'a' as a "source", 'b' as a "target" of module use
607 * - the module_use is added to the list of 'b' sources (so
608 * 'b' can walk the list to see who sourced them), and of 'a'
609 * targets (so 'a' can see what modules it targets).
611 static int add_module_usage(struct module *a, struct module *b)
613 struct module_use *use;
615 pr_debug("Allocating new usage for %s.\n", a->name);
616 use = kmalloc(sizeof(*use), GFP_ATOMIC);
617 if (!use) {
618 printk(KERN_WARNING "%s: out of memory loading\n", a->name);
619 return -ENOMEM;
622 use->source = a;
623 use->target = b;
624 list_add(&use->source_list, &b->source_list);
625 list_add(&use->target_list, &a->target_list);
626 return 0;
629 /* Module a uses b: caller needs module_mutex() */
630 int ref_module(struct module *a, struct module *b)
632 int err;
634 if (b == NULL || already_uses(a, b))
635 return 0;
637 /* If module isn't available, we fail. */
638 err = strong_try_module_get(b);
639 if (err)
640 return err;
642 err = add_module_usage(a, b);
643 if (err) {
644 module_put(b);
645 return err;
647 return 0;
649 EXPORT_SYMBOL_GPL(ref_module);
651 /* Clear the unload stuff of the module. */
652 static void module_unload_free(struct module *mod)
654 struct module_use *use, *tmp;
656 mutex_lock(&module_mutex);
657 list_for_each_entry_safe(use, tmp, &mod->target_list, target_list) {
658 struct module *i = use->target;
659 pr_debug("%s unusing %s\n", mod->name, i->name);
660 module_put(i);
661 list_del(&use->source_list);
662 list_del(&use->target_list);
663 kfree(use);
665 mutex_unlock(&module_mutex);
667 free_percpu(mod->refptr);
670 #ifdef CONFIG_MODULE_FORCE_UNLOAD
671 static inline int try_force_unload(unsigned int flags)
673 int ret = (flags & O_TRUNC);
674 if (ret)
675 add_taint(TAINT_FORCED_RMMOD);
676 return ret;
678 #else
679 static inline int try_force_unload(unsigned int flags)
681 return 0;
683 #endif /* CONFIG_MODULE_FORCE_UNLOAD */
685 struct stopref
687 struct module *mod;
688 int flags;
689 int *forced;
692 /* Whole machine is stopped with interrupts off when this runs. */
693 static int __try_stop_module(void *_sref)
695 struct stopref *sref = _sref;
697 /* If it's not unused, quit unless we're forcing. */
698 if (module_refcount(sref->mod) != 0) {
699 if (!(*sref->forced = try_force_unload(sref->flags)))
700 return -EWOULDBLOCK;
703 /* Mark it as dying. */
704 sref->mod->state = MODULE_STATE_GOING;
705 return 0;
708 static int try_stop_module(struct module *mod, int flags, int *forced)
710 if (flags & O_NONBLOCK) {
711 struct stopref sref = { mod, flags, forced };
713 return stop_machine(__try_stop_module, &sref, NULL);
714 } else {
715 /* We don't need to stop the machine for this. */
716 mod->state = MODULE_STATE_GOING;
717 synchronize_sched();
718 return 0;
722 unsigned long module_refcount(struct module *mod)
724 unsigned long incs = 0, decs = 0;
725 int cpu;
727 for_each_possible_cpu(cpu)
728 decs += per_cpu_ptr(mod->refptr, cpu)->decs;
730 * ensure the incs are added up after the decs.
731 * module_put ensures incs are visible before decs with smp_wmb.
733 * This 2-count scheme avoids the situation where the refcount
734 * for CPU0 is read, then CPU0 increments the module refcount,
735 * then CPU1 drops that refcount, then the refcount for CPU1 is
736 * read. We would record a decrement but not its corresponding
737 * increment so we would see a low count (disaster).
739 * Rare situation? But module_refcount can be preempted, and we
740 * might be tallying up 4096+ CPUs. So it is not impossible.
742 smp_rmb();
743 for_each_possible_cpu(cpu)
744 incs += per_cpu_ptr(mod->refptr, cpu)->incs;
745 return incs - decs;
747 EXPORT_SYMBOL(module_refcount);
749 /* This exists whether we can unload or not */
750 static void free_module(struct module *mod);
752 static void wait_for_zero_refcount(struct module *mod)
754 /* Since we might sleep for some time, release the mutex first */
755 mutex_unlock(&module_mutex);
756 for (;;) {
757 pr_debug("Looking at refcount...\n");
758 set_current_state(TASK_UNINTERRUPTIBLE);
759 if (module_refcount(mod) == 0)
760 break;
761 schedule();
763 current->state = TASK_RUNNING;
764 mutex_lock(&module_mutex);
767 SYSCALL_DEFINE2(delete_module, const char __user *, name_user,
768 unsigned int, flags)
770 struct module *mod;
771 char name[MODULE_NAME_LEN];
772 int ret, forced = 0;
774 if (!capable(CAP_SYS_MODULE) || modules_disabled)
775 return -EPERM;
777 if (strncpy_from_user(name, name_user, MODULE_NAME_LEN-1) < 0)
778 return -EFAULT;
779 name[MODULE_NAME_LEN-1] = '\0';
781 if (mutex_lock_interruptible(&module_mutex) != 0)
782 return -EINTR;
784 mod = find_module(name);
785 if (!mod) {
786 ret = -ENOENT;
787 goto out;
790 if (!list_empty(&mod->source_list)) {
791 /* Other modules depend on us: get rid of them first. */
792 ret = -EWOULDBLOCK;
793 goto out;
796 /* Doing init or already dying? */
797 if (mod->state != MODULE_STATE_LIVE) {
798 /* FIXME: if (force), slam module count and wake up
799 waiter --RR */
800 pr_debug("%s already dying\n", mod->name);
801 ret = -EBUSY;
802 goto out;
805 /* If it has an init func, it must have an exit func to unload */
806 if (mod->init && !mod->exit) {
807 forced = try_force_unload(flags);
808 if (!forced) {
809 /* This module can't be removed */
810 ret = -EBUSY;
811 goto out;
815 /* Set this up before setting mod->state */
816 mod->waiter = current;
818 /* Stop the machine so refcounts can't move and disable module. */
819 ret = try_stop_module(mod, flags, &forced);
820 if (ret != 0)
821 goto out;
823 /* Never wait if forced. */
824 if (!forced && module_refcount(mod) != 0)
825 wait_for_zero_refcount(mod);
827 mutex_unlock(&module_mutex);
828 /* Final destruction now no one is using it. */
829 if (mod->exit != NULL)
830 mod->exit();
831 blocking_notifier_call_chain(&module_notify_list,
832 MODULE_STATE_GOING, mod);
833 async_synchronize_full();
835 /* Store the name of the last unloaded module for diagnostic purposes */
836 strlcpy(last_unloaded_module, mod->name, sizeof(last_unloaded_module));
838 free_module(mod);
839 return 0;
840 out:
841 mutex_unlock(&module_mutex);
842 return ret;
845 static inline void print_unload_info(struct seq_file *m, struct module *mod)
847 struct module_use *use;
848 int printed_something = 0;
850 seq_printf(m, " %lu ", module_refcount(mod));
852 /* Always include a trailing , so userspace can differentiate
853 between this and the old multi-field proc format. */
854 list_for_each_entry(use, &mod->source_list, source_list) {
855 printed_something = 1;
856 seq_printf(m, "%s,", use->source->name);
859 if (mod->init != NULL && mod->exit == NULL) {
860 printed_something = 1;
861 seq_printf(m, "[permanent],");
864 if (!printed_something)
865 seq_printf(m, "-");
868 void __symbol_put(const char *symbol)
870 struct module *owner;
872 preempt_disable();
873 if (!find_symbol(symbol, &owner, NULL, true, false))
874 BUG();
875 module_put(owner);
876 preempt_enable();
878 EXPORT_SYMBOL(__symbol_put);
880 /* Note this assumes addr is a function, which it currently always is. */
881 void symbol_put_addr(void *addr)
883 struct module *modaddr;
884 unsigned long a = (unsigned long)dereference_function_descriptor(addr);
886 if (core_kernel_text(a))
887 return;
889 /* module_text_address is safe here: we're supposed to have reference
890 * to module from symbol_get, so it can't go away. */
891 modaddr = __module_text_address(a);
892 BUG_ON(!modaddr);
893 module_put(modaddr);
895 EXPORT_SYMBOL_GPL(symbol_put_addr);
897 static ssize_t show_refcnt(struct module_attribute *mattr,
898 struct module_kobject *mk, char *buffer)
900 return sprintf(buffer, "%lu\n", module_refcount(mk->mod));
903 static struct module_attribute modinfo_refcnt =
904 __ATTR(refcnt, 0444, show_refcnt, NULL);
906 void module_put(struct module *module)
908 if (module) {
909 preempt_disable();
910 smp_wmb(); /* see comment in module_refcount */
911 __this_cpu_inc(module->refptr->decs);
913 trace_module_put(module, _RET_IP_);
914 /* Maybe they're waiting for us to drop reference? */
915 if (unlikely(!module_is_live(module)))
916 wake_up_process(module->waiter);
917 preempt_enable();
920 EXPORT_SYMBOL(module_put);
922 #else /* !CONFIG_MODULE_UNLOAD */
923 static inline void print_unload_info(struct seq_file *m, struct module *mod)
925 /* We don't know the usage count, or what modules are using. */
926 seq_printf(m, " - -");
929 static inline void module_unload_free(struct module *mod)
933 int ref_module(struct module *a, struct module *b)
935 return strong_try_module_get(b);
937 EXPORT_SYMBOL_GPL(ref_module);
939 static inline int module_unload_init(struct module *mod)
941 return 0;
943 #endif /* CONFIG_MODULE_UNLOAD */
945 static size_t module_flags_taint(struct module *mod, char *buf)
947 size_t l = 0;
949 if (mod->taints & (1 << TAINT_PROPRIETARY_MODULE))
950 buf[l++] = 'P';
951 if (mod->taints & (1 << TAINT_OOT_MODULE))
952 buf[l++] = 'O';
953 if (mod->taints & (1 << TAINT_FORCED_MODULE))
954 buf[l++] = 'F';
955 if (mod->taints & (1 << TAINT_CRAP))
956 buf[l++] = 'C';
958 * TAINT_FORCED_RMMOD: could be added.
959 * TAINT_UNSAFE_SMP, TAINT_MACHINE_CHECK, TAINT_BAD_PAGE don't
960 * apply to modules.
962 return l;
965 static ssize_t show_initstate(struct module_attribute *mattr,
966 struct module_kobject *mk, char *buffer)
968 const char *state = "unknown";
970 switch (mk->mod->state) {
971 case MODULE_STATE_LIVE:
972 state = "live";
973 break;
974 case MODULE_STATE_COMING:
975 state = "coming";
976 break;
977 case MODULE_STATE_GOING:
978 state = "going";
979 break;
981 return sprintf(buffer, "%s\n", state);
984 static struct module_attribute modinfo_initstate =
985 __ATTR(initstate, 0444, show_initstate, NULL);
987 static ssize_t store_uevent(struct module_attribute *mattr,
988 struct module_kobject *mk,
989 const char *buffer, size_t count)
991 enum kobject_action action;
993 if (kobject_action_type(buffer, count, &action) == 0)
994 kobject_uevent(&mk->kobj, action);
995 return count;
998 struct module_attribute module_uevent =
999 __ATTR(uevent, 0200, NULL, store_uevent);
1001 static ssize_t show_coresize(struct module_attribute *mattr,
1002 struct module_kobject *mk, char *buffer)
1004 return sprintf(buffer, "%u\n", mk->mod->core_size);
1007 static struct module_attribute modinfo_coresize =
1008 __ATTR(coresize, 0444, show_coresize, NULL);
1010 static ssize_t show_initsize(struct module_attribute *mattr,
1011 struct module_kobject *mk, char *buffer)
1013 return sprintf(buffer, "%u\n", mk->mod->init_size);
1016 static struct module_attribute modinfo_initsize =
1017 __ATTR(initsize, 0444, show_initsize, NULL);
1019 static ssize_t show_taint(struct module_attribute *mattr,
1020 struct module_kobject *mk, char *buffer)
1022 size_t l;
1024 l = module_flags_taint(mk->mod, buffer);
1025 buffer[l++] = '\n';
1026 return l;
1029 static struct module_attribute modinfo_taint =
1030 __ATTR(taint, 0444, show_taint, NULL);
1032 static struct module_attribute *modinfo_attrs[] = {
1033 &module_uevent,
1034 &modinfo_version,
1035 &modinfo_srcversion,
1036 &modinfo_initstate,
1037 &modinfo_coresize,
1038 &modinfo_initsize,
1039 &modinfo_taint,
1040 #ifdef CONFIG_MODULE_UNLOAD
1041 &modinfo_refcnt,
1042 #endif
1043 NULL,
1046 static const char vermagic[] = VERMAGIC_STRING;
1048 static int try_to_force_load(struct module *mod, const char *reason)
1050 #ifdef CONFIG_MODULE_FORCE_LOAD
1051 if (!test_taint(TAINT_FORCED_MODULE))
1052 printk(KERN_WARNING "%s: %s: kernel tainted.\n",
1053 mod->name, reason);
1054 add_taint_module(mod, TAINT_FORCED_MODULE);
1055 return 0;
1056 #else
1057 return -ENOEXEC;
1058 #endif
1061 #ifdef CONFIG_MODVERSIONS
1062 /* If the arch applies (non-zero) relocations to kernel kcrctab, unapply it. */
1063 static unsigned long maybe_relocated(unsigned long crc,
1064 const struct module *crc_owner)
1066 #ifdef ARCH_RELOCATES_KCRCTAB
1067 if (crc_owner == NULL)
1068 return crc - (unsigned long)reloc_start;
1069 #endif
1070 return crc;
1073 static int check_version(Elf_Shdr *sechdrs,
1074 unsigned int versindex,
1075 const char *symname,
1076 struct module *mod,
1077 const unsigned long *crc,
1078 const struct module *crc_owner)
1080 unsigned int i, num_versions;
1081 struct modversion_info *versions;
1083 /* Exporting module didn't supply crcs? OK, we're already tainted. */
1084 if (!crc)
1085 return 1;
1087 /* No versions at all? modprobe --force does this. */
1088 if (versindex == 0)
1089 return try_to_force_load(mod, symname) == 0;
1091 versions = (void *) sechdrs[versindex].sh_addr;
1092 num_versions = sechdrs[versindex].sh_size
1093 / sizeof(struct modversion_info);
1095 for (i = 0; i < num_versions; i++) {
1096 if (strcmp(versions[i].name, symname) != 0)
1097 continue;
1099 if (versions[i].crc == maybe_relocated(*crc, crc_owner))
1100 return 1;
1101 pr_debug("Found checksum %lX vs module %lX\n",
1102 maybe_relocated(*crc, crc_owner), versions[i].crc);
1103 goto bad_version;
1106 printk(KERN_WARNING "%s: no symbol version for %s\n",
1107 mod->name, symname);
1108 return 0;
1110 bad_version:
1111 printk("%s: disagrees about version of symbol %s\n",
1112 mod->name, symname);
1113 return 0;
1116 static inline int check_modstruct_version(Elf_Shdr *sechdrs,
1117 unsigned int versindex,
1118 struct module *mod)
1120 const unsigned long *crc;
1122 /* Since this should be found in kernel (which can't be removed),
1123 * no locking is necessary. */
1124 if (!find_symbol(MODULE_SYMBOL_PREFIX "module_layout", NULL,
1125 &crc, true, false))
1126 BUG();
1127 return check_version(sechdrs, versindex, "module_layout", mod, crc,
1128 NULL);
1131 /* First part is kernel version, which we ignore if module has crcs. */
1132 static inline int same_magic(const char *amagic, const char *bmagic,
1133 bool has_crcs)
1135 if (has_crcs) {
1136 amagic += strcspn(amagic, " ");
1137 bmagic += strcspn(bmagic, " ");
1139 return strcmp(amagic, bmagic) == 0;
1141 #else
1142 static inline int check_version(Elf_Shdr *sechdrs,
1143 unsigned int versindex,
1144 const char *symname,
1145 struct module *mod,
1146 const unsigned long *crc,
1147 const struct module *crc_owner)
1149 return 1;
1152 static inline int check_modstruct_version(Elf_Shdr *sechdrs,
1153 unsigned int versindex,
1154 struct module *mod)
1156 return 1;
1159 static inline int same_magic(const char *amagic, const char *bmagic,
1160 bool has_crcs)
1162 return strcmp(amagic, bmagic) == 0;
1164 #endif /* CONFIG_MODVERSIONS */
1166 /* Resolve a symbol for this module. I.e. if we find one, record usage. */
1167 static const struct kernel_symbol *resolve_symbol(struct module *mod,
1168 const struct load_info *info,
1169 const char *name,
1170 char ownername[])
1172 struct module *owner;
1173 const struct kernel_symbol *sym;
1174 const unsigned long *crc;
1175 int err;
1177 mutex_lock(&module_mutex);
1178 sym = find_symbol(name, &owner, &crc,
1179 !(mod->taints & (1 << TAINT_PROPRIETARY_MODULE)), true);
1180 if (!sym)
1181 goto unlock;
1183 if (!check_version(info->sechdrs, info->index.vers, name, mod, crc,
1184 owner)) {
1185 sym = ERR_PTR(-EINVAL);
1186 goto getname;
1189 err = ref_module(mod, owner);
1190 if (err) {
1191 sym = ERR_PTR(err);
1192 goto getname;
1195 getname:
1196 /* We must make copy under the lock if we failed to get ref. */
1197 strncpy(ownername, module_name(owner), MODULE_NAME_LEN);
1198 unlock:
1199 mutex_unlock(&module_mutex);
1200 return sym;
1203 static const struct kernel_symbol *
1204 resolve_symbol_wait(struct module *mod,
1205 const struct load_info *info,
1206 const char *name)
1208 const struct kernel_symbol *ksym;
1209 char owner[MODULE_NAME_LEN];
1211 if (wait_event_interruptible_timeout(module_wq,
1212 !IS_ERR(ksym = resolve_symbol(mod, info, name, owner))
1213 || PTR_ERR(ksym) != -EBUSY,
1214 30 * HZ) <= 0) {
1215 printk(KERN_WARNING "%s: gave up waiting for init of module %s.\n",
1216 mod->name, owner);
1218 return ksym;
1222 * /sys/module/foo/sections stuff
1223 * J. Corbet <corbet@lwn.net>
1225 #ifdef CONFIG_SYSFS
1227 #ifdef CONFIG_KALLSYMS
1228 static inline bool sect_empty(const Elf_Shdr *sect)
1230 return !(sect->sh_flags & SHF_ALLOC) || sect->sh_size == 0;
1233 struct module_sect_attr
1235 struct module_attribute mattr;
1236 char *name;
1237 unsigned long address;
1240 struct module_sect_attrs
1242 struct attribute_group grp;
1243 unsigned int nsections;
1244 struct module_sect_attr attrs[0];
1247 static ssize_t module_sect_show(struct module_attribute *mattr,
1248 struct module_kobject *mk, char *buf)
1250 struct module_sect_attr *sattr =
1251 container_of(mattr, struct module_sect_attr, mattr);
1252 return sprintf(buf, "0x%pK\n", (void *)sattr->address);
1255 static void free_sect_attrs(struct module_sect_attrs *sect_attrs)
1257 unsigned int section;
1259 for (section = 0; section < sect_attrs->nsections; section++)
1260 kfree(sect_attrs->attrs[section].name);
1261 kfree(sect_attrs);
1264 static void add_sect_attrs(struct module *mod, const struct load_info *info)
1266 unsigned int nloaded = 0, i, size[2];
1267 struct module_sect_attrs *sect_attrs;
1268 struct module_sect_attr *sattr;
1269 struct attribute **gattr;
1271 /* Count loaded sections and allocate structures */
1272 for (i = 0; i < info->hdr->e_shnum; i++)
1273 if (!sect_empty(&info->sechdrs[i]))
1274 nloaded++;
1275 size[0] = ALIGN(sizeof(*sect_attrs)
1276 + nloaded * sizeof(sect_attrs->attrs[0]),
1277 sizeof(sect_attrs->grp.attrs[0]));
1278 size[1] = (nloaded + 1) * sizeof(sect_attrs->grp.attrs[0]);
1279 sect_attrs = kzalloc(size[0] + size[1], GFP_KERNEL);
1280 if (sect_attrs == NULL)
1281 return;
1283 /* Setup section attributes. */
1284 sect_attrs->grp.name = "sections";
1285 sect_attrs->grp.attrs = (void *)sect_attrs + size[0];
1287 sect_attrs->nsections = 0;
1288 sattr = &sect_attrs->attrs[0];
1289 gattr = &sect_attrs->grp.attrs[0];
1290 for (i = 0; i < info->hdr->e_shnum; i++) {
1291 Elf_Shdr *sec = &info->sechdrs[i];
1292 if (sect_empty(sec))
1293 continue;
1294 sattr->address = sec->sh_addr;
1295 sattr->name = kstrdup(info->secstrings + sec->sh_name,
1296 GFP_KERNEL);
1297 if (sattr->name == NULL)
1298 goto out;
1299 sect_attrs->nsections++;
1300 sysfs_attr_init(&sattr->mattr.attr);
1301 sattr->mattr.show = module_sect_show;
1302 sattr->mattr.store = NULL;
1303 sattr->mattr.attr.name = sattr->name;
1304 sattr->mattr.attr.mode = S_IRUGO;
1305 *(gattr++) = &(sattr++)->mattr.attr;
1307 *gattr = NULL;
1309 if (sysfs_create_group(&mod->mkobj.kobj, &sect_attrs->grp))
1310 goto out;
1312 mod->sect_attrs = sect_attrs;
1313 return;
1314 out:
1315 free_sect_attrs(sect_attrs);
1318 static void remove_sect_attrs(struct module *mod)
1320 if (mod->sect_attrs) {
1321 sysfs_remove_group(&mod->mkobj.kobj,
1322 &mod->sect_attrs->grp);
1323 /* We are positive that no one is using any sect attrs
1324 * at this point. Deallocate immediately. */
1325 free_sect_attrs(mod->sect_attrs);
1326 mod->sect_attrs = NULL;
1331 * /sys/module/foo/notes/.section.name gives contents of SHT_NOTE sections.
1334 struct module_notes_attrs {
1335 struct kobject *dir;
1336 unsigned int notes;
1337 struct bin_attribute attrs[0];
1340 static ssize_t module_notes_read(struct file *filp, struct kobject *kobj,
1341 struct bin_attribute *bin_attr,
1342 char *buf, loff_t pos, size_t count)
1345 * The caller checked the pos and count against our size.
1347 memcpy(buf, bin_attr->private + pos, count);
1348 return count;
1351 static void free_notes_attrs(struct module_notes_attrs *notes_attrs,
1352 unsigned int i)
1354 if (notes_attrs->dir) {
1355 while (i-- > 0)
1356 sysfs_remove_bin_file(notes_attrs->dir,
1357 &notes_attrs->attrs[i]);
1358 kobject_put(notes_attrs->dir);
1360 kfree(notes_attrs);
1363 static void add_notes_attrs(struct module *mod, const struct load_info *info)
1365 unsigned int notes, loaded, i;
1366 struct module_notes_attrs *notes_attrs;
1367 struct bin_attribute *nattr;
1369 /* failed to create section attributes, so can't create notes */
1370 if (!mod->sect_attrs)
1371 return;
1373 /* Count notes sections and allocate structures. */
1374 notes = 0;
1375 for (i = 0; i < info->hdr->e_shnum; i++)
1376 if (!sect_empty(&info->sechdrs[i]) &&
1377 (info->sechdrs[i].sh_type == SHT_NOTE))
1378 ++notes;
1380 if (notes == 0)
1381 return;
1383 notes_attrs = kzalloc(sizeof(*notes_attrs)
1384 + notes * sizeof(notes_attrs->attrs[0]),
1385 GFP_KERNEL);
1386 if (notes_attrs == NULL)
1387 return;
1389 notes_attrs->notes = notes;
1390 nattr = &notes_attrs->attrs[0];
1391 for (loaded = i = 0; i < info->hdr->e_shnum; ++i) {
1392 if (sect_empty(&info->sechdrs[i]))
1393 continue;
1394 if (info->sechdrs[i].sh_type == SHT_NOTE) {
1395 sysfs_bin_attr_init(nattr);
1396 nattr->attr.name = mod->sect_attrs->attrs[loaded].name;
1397 nattr->attr.mode = S_IRUGO;
1398 nattr->size = info->sechdrs[i].sh_size;
1399 nattr->private = (void *) info->sechdrs[i].sh_addr;
1400 nattr->read = module_notes_read;
1401 ++nattr;
1403 ++loaded;
1406 notes_attrs->dir = kobject_create_and_add("notes", &mod->mkobj.kobj);
1407 if (!notes_attrs->dir)
1408 goto out;
1410 for (i = 0; i < notes; ++i)
1411 if (sysfs_create_bin_file(notes_attrs->dir,
1412 &notes_attrs->attrs[i]))
1413 goto out;
1415 mod->notes_attrs = notes_attrs;
1416 return;
1418 out:
1419 free_notes_attrs(notes_attrs, i);
1422 static void remove_notes_attrs(struct module *mod)
1424 if (mod->notes_attrs)
1425 free_notes_attrs(mod->notes_attrs, mod->notes_attrs->notes);
1428 #else
1430 static inline void add_sect_attrs(struct module *mod,
1431 const struct load_info *info)
1435 static inline void remove_sect_attrs(struct module *mod)
1439 static inline void add_notes_attrs(struct module *mod,
1440 const struct load_info *info)
1444 static inline void remove_notes_attrs(struct module *mod)
1447 #endif /* CONFIG_KALLSYMS */
1449 static void add_usage_links(struct module *mod)
1451 #ifdef CONFIG_MODULE_UNLOAD
1452 struct module_use *use;
1453 int nowarn;
1455 mutex_lock(&module_mutex);
1456 list_for_each_entry(use, &mod->target_list, target_list) {
1457 nowarn = sysfs_create_link(use->target->holders_dir,
1458 &mod->mkobj.kobj, mod->name);
1460 mutex_unlock(&module_mutex);
1461 #endif
1464 static void del_usage_links(struct module *mod)
1466 #ifdef CONFIG_MODULE_UNLOAD
1467 struct module_use *use;
1469 mutex_lock(&module_mutex);
1470 list_for_each_entry(use, &mod->target_list, target_list)
1471 sysfs_remove_link(use->target->holders_dir, mod->name);
1472 mutex_unlock(&module_mutex);
1473 #endif
1476 static int module_add_modinfo_attrs(struct module *mod)
1478 struct module_attribute *attr;
1479 struct module_attribute *temp_attr;
1480 int error = 0;
1481 int i;
1483 mod->modinfo_attrs = kzalloc((sizeof(struct module_attribute) *
1484 (ARRAY_SIZE(modinfo_attrs) + 1)),
1485 GFP_KERNEL);
1486 if (!mod->modinfo_attrs)
1487 return -ENOMEM;
1489 temp_attr = mod->modinfo_attrs;
1490 for (i = 0; (attr = modinfo_attrs[i]) && !error; i++) {
1491 if (!attr->test ||
1492 (attr->test && attr->test(mod))) {
1493 memcpy(temp_attr, attr, sizeof(*temp_attr));
1494 sysfs_attr_init(&temp_attr->attr);
1495 error = sysfs_create_file(&mod->mkobj.kobj,&temp_attr->attr);
1496 ++temp_attr;
1499 return error;
1502 static void module_remove_modinfo_attrs(struct module *mod)
1504 struct module_attribute *attr;
1505 int i;
1507 for (i = 0; (attr = &mod->modinfo_attrs[i]); i++) {
1508 /* pick a field to test for end of list */
1509 if (!attr->attr.name)
1510 break;
1511 sysfs_remove_file(&mod->mkobj.kobj,&attr->attr);
1512 if (attr->free)
1513 attr->free(mod);
1515 kfree(mod->modinfo_attrs);
1518 static int mod_sysfs_init(struct module *mod)
1520 int err;
1521 struct kobject *kobj;
1523 if (!module_sysfs_initialized) {
1524 printk(KERN_ERR "%s: module sysfs not initialized\n",
1525 mod->name);
1526 err = -EINVAL;
1527 goto out;
1530 kobj = kset_find_obj(module_kset, mod->name);
1531 if (kobj) {
1532 printk(KERN_ERR "%s: module is already loaded\n", mod->name);
1533 kobject_put(kobj);
1534 err = -EINVAL;
1535 goto out;
1538 mod->mkobj.mod = mod;
1540 memset(&mod->mkobj.kobj, 0, sizeof(mod->mkobj.kobj));
1541 mod->mkobj.kobj.kset = module_kset;
1542 err = kobject_init_and_add(&mod->mkobj.kobj, &module_ktype, NULL,
1543 "%s", mod->name);
1544 if (err)
1545 kobject_put(&mod->mkobj.kobj);
1547 /* delay uevent until full sysfs population */
1548 out:
1549 return err;
1552 static int mod_sysfs_setup(struct module *mod,
1553 const struct load_info *info,
1554 struct kernel_param *kparam,
1555 unsigned int num_params)
1557 int err;
1559 err = mod_sysfs_init(mod);
1560 if (err)
1561 goto out;
1563 mod->holders_dir = kobject_create_and_add("holders", &mod->mkobj.kobj);
1564 if (!mod->holders_dir) {
1565 err = -ENOMEM;
1566 goto out_unreg;
1569 err = module_param_sysfs_setup(mod, kparam, num_params);
1570 if (err)
1571 goto out_unreg_holders;
1573 err = module_add_modinfo_attrs(mod);
1574 if (err)
1575 goto out_unreg_param;
1577 add_usage_links(mod);
1578 add_sect_attrs(mod, info);
1579 add_notes_attrs(mod, info);
1581 kobject_uevent(&mod->mkobj.kobj, KOBJ_ADD);
1582 return 0;
1584 out_unreg_param:
1585 module_param_sysfs_remove(mod);
1586 out_unreg_holders:
1587 kobject_put(mod->holders_dir);
1588 out_unreg:
1589 kobject_put(&mod->mkobj.kobj);
1590 out:
1591 return err;
1594 static void mod_sysfs_fini(struct module *mod)
1596 remove_notes_attrs(mod);
1597 remove_sect_attrs(mod);
1598 kobject_put(&mod->mkobj.kobj);
1601 #else /* !CONFIG_SYSFS */
1603 static int mod_sysfs_setup(struct module *mod,
1604 const struct load_info *info,
1605 struct kernel_param *kparam,
1606 unsigned int num_params)
1608 return 0;
1611 static void mod_sysfs_fini(struct module *mod)
1615 static void module_remove_modinfo_attrs(struct module *mod)
1619 static void del_usage_links(struct module *mod)
1623 #endif /* CONFIG_SYSFS */
1625 static void mod_sysfs_teardown(struct module *mod)
1627 del_usage_links(mod);
1628 module_remove_modinfo_attrs(mod);
1629 module_param_sysfs_remove(mod);
1630 kobject_put(mod->mkobj.drivers_dir);
1631 kobject_put(mod->holders_dir);
1632 mod_sysfs_fini(mod);
1636 * unlink the module with the whole machine is stopped with interrupts off
1637 * - this defends against kallsyms not taking locks
1639 static int __unlink_module(void *_mod)
1641 struct module *mod = _mod;
1642 list_del(&mod->list);
1643 module_bug_cleanup(mod);
1644 return 0;
1647 #ifdef CONFIG_DEBUG_SET_MODULE_RONX
1649 * LKM RO/NX protection: protect module's text/ro-data
1650 * from modification and any data from execution.
1652 void set_page_attributes(void *start, void *end, int (*set)(unsigned long start, int num_pages))
1654 unsigned long begin_pfn = PFN_DOWN((unsigned long)start);
1655 unsigned long end_pfn = PFN_DOWN((unsigned long)end);
1657 if (end_pfn > begin_pfn)
1658 set(begin_pfn << PAGE_SHIFT, end_pfn - begin_pfn);
1661 static void set_section_ro_nx(void *base,
1662 unsigned long text_size,
1663 unsigned long ro_size,
1664 unsigned long total_size)
1666 /* begin and end PFNs of the current subsection */
1667 unsigned long begin_pfn;
1668 unsigned long end_pfn;
1671 * Set RO for module text and RO-data:
1672 * - Always protect first page.
1673 * - Do not protect last partial page.
1675 if (ro_size > 0)
1676 set_page_attributes(base, base + ro_size, set_memory_ro);
1679 * Set NX permissions for module data:
1680 * - Do not protect first partial page.
1681 * - Always protect last page.
1683 if (total_size > text_size) {
1684 begin_pfn = PFN_UP((unsigned long)base + text_size);
1685 end_pfn = PFN_UP((unsigned long)base + total_size);
1686 if (end_pfn > begin_pfn)
1687 set_memory_nx(begin_pfn << PAGE_SHIFT, end_pfn - begin_pfn);
1691 static void unset_module_core_ro_nx(struct module *mod)
1693 set_page_attributes(mod->module_core + mod->core_text_size,
1694 mod->module_core + mod->core_size,
1695 set_memory_x);
1696 set_page_attributes(mod->module_core,
1697 mod->module_core + mod->core_ro_size,
1698 set_memory_rw);
1701 static void unset_module_init_ro_nx(struct module *mod)
1703 set_page_attributes(mod->module_init + mod->init_text_size,
1704 mod->module_init + mod->init_size,
1705 set_memory_x);
1706 set_page_attributes(mod->module_init,
1707 mod->module_init + mod->init_ro_size,
1708 set_memory_rw);
1711 /* Iterate through all modules and set each module's text as RW */
1712 void set_all_modules_text_rw(void)
1714 struct module *mod;
1716 mutex_lock(&module_mutex);
1717 list_for_each_entry_rcu(mod, &modules, list) {
1718 if ((mod->module_core) && (mod->core_text_size)) {
1719 set_page_attributes(mod->module_core,
1720 mod->module_core + mod->core_text_size,
1721 set_memory_rw);
1723 if ((mod->module_init) && (mod->init_text_size)) {
1724 set_page_attributes(mod->module_init,
1725 mod->module_init + mod->init_text_size,
1726 set_memory_rw);
1729 mutex_unlock(&module_mutex);
1732 /* Iterate through all modules and set each module's text as RO */
1733 void set_all_modules_text_ro(void)
1735 struct module *mod;
1737 mutex_lock(&module_mutex);
1738 list_for_each_entry_rcu(mod, &modules, list) {
1739 if ((mod->module_core) && (mod->core_text_size)) {
1740 set_page_attributes(mod->module_core,
1741 mod->module_core + mod->core_text_size,
1742 set_memory_ro);
1744 if ((mod->module_init) && (mod->init_text_size)) {
1745 set_page_attributes(mod->module_init,
1746 mod->module_init + mod->init_text_size,
1747 set_memory_ro);
1750 mutex_unlock(&module_mutex);
1752 #else
1753 static inline void set_section_ro_nx(void *base, unsigned long text_size, unsigned long ro_size, unsigned long total_size) { }
1754 static void unset_module_core_ro_nx(struct module *mod) { }
1755 static void unset_module_init_ro_nx(struct module *mod) { }
1756 #endif
1758 void __weak module_free(struct module *mod, void *module_region)
1760 vfree(module_region);
1763 void __weak module_arch_cleanup(struct module *mod)
1767 /* Free a module, remove from lists, etc. */
1768 static void free_module(struct module *mod)
1770 trace_module_free(mod);
1772 /* Delete from various lists */
1773 mutex_lock(&module_mutex);
1774 stop_machine(__unlink_module, mod, NULL);
1775 mutex_unlock(&module_mutex);
1776 mod_sysfs_teardown(mod);
1778 /* Remove dynamic debug info */
1779 ddebug_remove_module(mod->name);
1781 /* Arch-specific cleanup. */
1782 module_arch_cleanup(mod);
1784 /* Module unload stuff */
1785 module_unload_free(mod);
1787 /* Free any allocated parameters. */
1788 destroy_params(mod->kp, mod->num_kp);
1790 /* This may be NULL, but that's OK */
1791 unset_module_init_ro_nx(mod);
1792 module_free(mod, mod->module_init);
1793 kfree(mod->args);
1794 percpu_modfree(mod);
1796 /* Free lock-classes: */
1797 lockdep_free_key_range(mod->module_core, mod->core_size);
1799 /* Finally, free the core (containing the module structure) */
1800 unset_module_core_ro_nx(mod);
1801 module_free(mod, mod->module_core);
1803 #ifdef CONFIG_MPU
1804 update_protections(current->mm);
1805 #endif
1808 void *__symbol_get(const char *symbol)
1810 struct module *owner;
1811 const struct kernel_symbol *sym;
1813 preempt_disable();
1814 sym = find_symbol(symbol, &owner, NULL, true, true);
1815 if (sym && strong_try_module_get(owner))
1816 sym = NULL;
1817 preempt_enable();
1819 return sym ? (void *)sym->value : NULL;
1821 EXPORT_SYMBOL_GPL(__symbol_get);
1824 * Ensure that an exported symbol [global namespace] does not already exist
1825 * in the kernel or in some other module's exported symbol table.
1827 * You must hold the module_mutex.
1829 static int verify_export_symbols(struct module *mod)
1831 unsigned int i;
1832 struct module *owner;
1833 const struct kernel_symbol *s;
1834 struct {
1835 const struct kernel_symbol *sym;
1836 unsigned int num;
1837 } arr[] = {
1838 { mod->syms, mod->num_syms },
1839 { mod->gpl_syms, mod->num_gpl_syms },
1840 { mod->gpl_future_syms, mod->num_gpl_future_syms },
1841 #ifdef CONFIG_UNUSED_SYMBOLS
1842 { mod->unused_syms, mod->num_unused_syms },
1843 { mod->unused_gpl_syms, mod->num_unused_gpl_syms },
1844 #endif
1847 for (i = 0; i < ARRAY_SIZE(arr); i++) {
1848 for (s = arr[i].sym; s < arr[i].sym + arr[i].num; s++) {
1849 if (find_symbol(s->name, &owner, NULL, true, false)) {
1850 printk(KERN_ERR
1851 "%s: exports duplicate symbol %s"
1852 " (owned by %s)\n",
1853 mod->name, s->name, module_name(owner));
1854 return -ENOEXEC;
1858 return 0;
1861 /* Change all symbols so that st_value encodes the pointer directly. */
1862 static int simplify_symbols(struct module *mod, const struct load_info *info)
1864 Elf_Shdr *symsec = &info->sechdrs[info->index.sym];
1865 Elf_Sym *sym = (void *)symsec->sh_addr;
1866 unsigned long secbase;
1867 unsigned int i;
1868 int ret = 0;
1869 const struct kernel_symbol *ksym;
1871 for (i = 1; i < symsec->sh_size / sizeof(Elf_Sym); i++) {
1872 const char *name = info->strtab + sym[i].st_name;
1874 switch (sym[i].st_shndx) {
1875 case SHN_COMMON:
1876 /* We compiled with -fno-common. These are not
1877 supposed to happen. */
1878 pr_debug("Common symbol: %s\n", name);
1879 printk("%s: please compile with -fno-common\n",
1880 mod->name);
1881 ret = -ENOEXEC;
1882 break;
1884 case SHN_ABS:
1885 /* Don't need to do anything */
1886 pr_debug("Absolute symbol: 0x%08lx\n",
1887 (long)sym[i].st_value);
1888 break;
1890 case SHN_UNDEF:
1891 ksym = resolve_symbol_wait(mod, info, name);
1892 /* Ok if resolved. */
1893 if (ksym && !IS_ERR(ksym)) {
1894 sym[i].st_value = ksym->value;
1895 break;
1898 /* Ok if weak. */
1899 if (!ksym && ELF_ST_BIND(sym[i].st_info) == STB_WEAK)
1900 break;
1902 printk(KERN_WARNING "%s: Unknown symbol %s (err %li)\n",
1903 mod->name, name, PTR_ERR(ksym));
1904 ret = PTR_ERR(ksym) ?: -ENOENT;
1905 break;
1907 default:
1908 /* Divert to percpu allocation if a percpu var. */
1909 if (sym[i].st_shndx == info->index.pcpu)
1910 secbase = (unsigned long)mod_percpu(mod);
1911 else
1912 secbase = info->sechdrs[sym[i].st_shndx].sh_addr;
1913 sym[i].st_value += secbase;
1914 break;
1918 return ret;
1921 int __weak apply_relocate(Elf_Shdr *sechdrs,
1922 const char *strtab,
1923 unsigned int symindex,
1924 unsigned int relsec,
1925 struct module *me)
1927 pr_err("module %s: REL relocation unsupported\n", me->name);
1928 return -ENOEXEC;
1931 int __weak apply_relocate_add(Elf_Shdr *sechdrs,
1932 const char *strtab,
1933 unsigned int symindex,
1934 unsigned int relsec,
1935 struct module *me)
1937 pr_err("module %s: RELA relocation unsupported\n", me->name);
1938 return -ENOEXEC;
1941 static int apply_relocations(struct module *mod, const struct load_info *info)
1943 unsigned int i;
1944 int err = 0;
1946 /* Now do relocations. */
1947 for (i = 1; i < info->hdr->e_shnum; i++) {
1948 unsigned int infosec = info->sechdrs[i].sh_info;
1950 /* Not a valid relocation section? */
1951 if (infosec >= info->hdr->e_shnum)
1952 continue;
1954 /* Don't bother with non-allocated sections */
1955 if (!(info->sechdrs[infosec].sh_flags & SHF_ALLOC))
1956 continue;
1958 if (info->sechdrs[i].sh_type == SHT_REL)
1959 err = apply_relocate(info->sechdrs, info->strtab,
1960 info->index.sym, i, mod);
1961 else if (info->sechdrs[i].sh_type == SHT_RELA)
1962 err = apply_relocate_add(info->sechdrs, info->strtab,
1963 info->index.sym, i, mod);
1964 if (err < 0)
1965 break;
1967 return err;
1970 /* Additional bytes needed by arch in front of individual sections */
1971 unsigned int __weak arch_mod_section_prepend(struct module *mod,
1972 unsigned int section)
1974 /* default implementation just returns zero */
1975 return 0;
1978 /* Update size with this section: return offset. */
1979 static long get_offset(struct module *mod, unsigned int *size,
1980 Elf_Shdr *sechdr, unsigned int section)
1982 long ret;
1984 *size += arch_mod_section_prepend(mod, section);
1985 ret = ALIGN(*size, sechdr->sh_addralign ?: 1);
1986 *size = ret + sechdr->sh_size;
1987 return ret;
1990 /* Lay out the SHF_ALLOC sections in a way not dissimilar to how ld
1991 might -- code, read-only data, read-write data, small data. Tally
1992 sizes, and place the offsets into sh_entsize fields: high bit means it
1993 belongs in init. */
1994 static void layout_sections(struct module *mod, struct load_info *info)
1996 static unsigned long const masks[][2] = {
1997 /* NOTE: all executable code must be the first section
1998 * in this array; otherwise modify the text_size
1999 * finder in the two loops below */
2000 { SHF_EXECINSTR | SHF_ALLOC, ARCH_SHF_SMALL },
2001 { SHF_ALLOC, SHF_WRITE | ARCH_SHF_SMALL },
2002 { SHF_WRITE | SHF_ALLOC, ARCH_SHF_SMALL },
2003 { ARCH_SHF_SMALL | SHF_ALLOC, 0 }
2005 unsigned int m, i;
2007 for (i = 0; i < info->hdr->e_shnum; i++)
2008 info->sechdrs[i].sh_entsize = ~0UL;
2010 pr_debug("Core section allocation order:\n");
2011 for (m = 0; m < ARRAY_SIZE(masks); ++m) {
2012 for (i = 0; i < info->hdr->e_shnum; ++i) {
2013 Elf_Shdr *s = &info->sechdrs[i];
2014 const char *sname = info->secstrings + s->sh_name;
2016 if ((s->sh_flags & masks[m][0]) != masks[m][0]
2017 || (s->sh_flags & masks[m][1])
2018 || s->sh_entsize != ~0UL
2019 || strstarts(sname, ".init"))
2020 continue;
2021 s->sh_entsize = get_offset(mod, &mod->core_size, s, i);
2022 pr_debug("\t%s\n", sname);
2024 switch (m) {
2025 case 0: /* executable */
2026 mod->core_size = debug_align(mod->core_size);
2027 mod->core_text_size = mod->core_size;
2028 break;
2029 case 1: /* RO: text and ro-data */
2030 mod->core_size = debug_align(mod->core_size);
2031 mod->core_ro_size = mod->core_size;
2032 break;
2033 case 3: /* whole core */
2034 mod->core_size = debug_align(mod->core_size);
2035 break;
2039 pr_debug("Init section allocation order:\n");
2040 for (m = 0; m < ARRAY_SIZE(masks); ++m) {
2041 for (i = 0; i < info->hdr->e_shnum; ++i) {
2042 Elf_Shdr *s = &info->sechdrs[i];
2043 const char *sname = info->secstrings + s->sh_name;
2045 if ((s->sh_flags & masks[m][0]) != masks[m][0]
2046 || (s->sh_flags & masks[m][1])
2047 || s->sh_entsize != ~0UL
2048 || !strstarts(sname, ".init"))
2049 continue;
2050 s->sh_entsize = (get_offset(mod, &mod->init_size, s, i)
2051 | INIT_OFFSET_MASK);
2052 pr_debug("\t%s\n", sname);
2054 switch (m) {
2055 case 0: /* executable */
2056 mod->init_size = debug_align(mod->init_size);
2057 mod->init_text_size = mod->init_size;
2058 break;
2059 case 1: /* RO: text and ro-data */
2060 mod->init_size = debug_align(mod->init_size);
2061 mod->init_ro_size = mod->init_size;
2062 break;
2063 case 3: /* whole init */
2064 mod->init_size = debug_align(mod->init_size);
2065 break;
2070 static void set_license(struct module *mod, const char *license)
2072 if (!license)
2073 license = "unspecified";
2075 if (!license_is_gpl_compatible(license)) {
2076 if (!test_taint(TAINT_PROPRIETARY_MODULE))
2077 printk(KERN_WARNING "%s: module license '%s' taints "
2078 "kernel.\n", mod->name, license);
2079 add_taint_module(mod, TAINT_PROPRIETARY_MODULE);
2083 /* Parse tag=value strings from .modinfo section */
2084 static char *next_string(char *string, unsigned long *secsize)
2086 /* Skip non-zero chars */
2087 while (string[0]) {
2088 string++;
2089 if ((*secsize)-- <= 1)
2090 return NULL;
2093 /* Skip any zero padding. */
2094 while (!string[0]) {
2095 string++;
2096 if ((*secsize)-- <= 1)
2097 return NULL;
2099 return string;
2102 static char *get_modinfo(struct load_info *info, const char *tag)
2104 char *p;
2105 unsigned int taglen = strlen(tag);
2106 Elf_Shdr *infosec = &info->sechdrs[info->index.info];
2107 unsigned long size = infosec->sh_size;
2109 for (p = (char *)infosec->sh_addr; p; p = next_string(p, &size)) {
2110 if (strncmp(p, tag, taglen) == 0 && p[taglen] == '=')
2111 return p + taglen + 1;
2113 return NULL;
2116 static void setup_modinfo(struct module *mod, struct load_info *info)
2118 struct module_attribute *attr;
2119 int i;
2121 for (i = 0; (attr = modinfo_attrs[i]); i++) {
2122 if (attr->setup)
2123 attr->setup(mod, get_modinfo(info, attr->attr.name));
2127 static void free_modinfo(struct module *mod)
2129 struct module_attribute *attr;
2130 int i;
2132 for (i = 0; (attr = modinfo_attrs[i]); i++) {
2133 if (attr->free)
2134 attr->free(mod);
2138 #ifdef CONFIG_KALLSYMS
2140 /* lookup symbol in given range of kernel_symbols */
2141 static const struct kernel_symbol *lookup_symbol(const char *name,
2142 const struct kernel_symbol *start,
2143 const struct kernel_symbol *stop)
2145 return bsearch(name, start, stop - start,
2146 sizeof(struct kernel_symbol), cmp_name);
2149 static int is_exported(const char *name, unsigned long value,
2150 const struct module *mod)
2152 const struct kernel_symbol *ks;
2153 if (!mod)
2154 ks = lookup_symbol(name, __start___ksymtab, __stop___ksymtab);
2155 else
2156 ks = lookup_symbol(name, mod->syms, mod->syms + mod->num_syms);
2157 return ks != NULL && ks->value == value;
2160 /* As per nm */
2161 static char elf_type(const Elf_Sym *sym, const struct load_info *info)
2163 const Elf_Shdr *sechdrs = info->sechdrs;
2165 if (ELF_ST_BIND(sym->st_info) == STB_WEAK) {
2166 if (ELF_ST_TYPE(sym->st_info) == STT_OBJECT)
2167 return 'v';
2168 else
2169 return 'w';
2171 if (sym->st_shndx == SHN_UNDEF)
2172 return 'U';
2173 if (sym->st_shndx == SHN_ABS)
2174 return 'a';
2175 if (sym->st_shndx >= SHN_LORESERVE)
2176 return '?';
2177 if (sechdrs[sym->st_shndx].sh_flags & SHF_EXECINSTR)
2178 return 't';
2179 if (sechdrs[sym->st_shndx].sh_flags & SHF_ALLOC
2180 && sechdrs[sym->st_shndx].sh_type != SHT_NOBITS) {
2181 if (!(sechdrs[sym->st_shndx].sh_flags & SHF_WRITE))
2182 return 'r';
2183 else if (sechdrs[sym->st_shndx].sh_flags & ARCH_SHF_SMALL)
2184 return 'g';
2185 else
2186 return 'd';
2188 if (sechdrs[sym->st_shndx].sh_type == SHT_NOBITS) {
2189 if (sechdrs[sym->st_shndx].sh_flags & ARCH_SHF_SMALL)
2190 return 's';
2191 else
2192 return 'b';
2194 if (strstarts(info->secstrings + sechdrs[sym->st_shndx].sh_name,
2195 ".debug")) {
2196 return 'n';
2198 return '?';
2201 static bool is_core_symbol(const Elf_Sym *src, const Elf_Shdr *sechdrs,
2202 unsigned int shnum)
2204 const Elf_Shdr *sec;
2206 if (src->st_shndx == SHN_UNDEF
2207 || src->st_shndx >= shnum
2208 || !src->st_name)
2209 return false;
2211 sec = sechdrs + src->st_shndx;
2212 if (!(sec->sh_flags & SHF_ALLOC)
2213 #ifndef CONFIG_KALLSYMS_ALL
2214 || !(sec->sh_flags & SHF_EXECINSTR)
2215 #endif
2216 || (sec->sh_entsize & INIT_OFFSET_MASK))
2217 return false;
2219 return true;
2223 * We only allocate and copy the strings needed by the parts of symtab
2224 * we keep. This is simple, but has the effect of making multiple
2225 * copies of duplicates. We could be more sophisticated, see
2226 * linux-kernel thread starting with
2227 * <73defb5e4bca04a6431392cc341112b1@localhost>.
2229 static void layout_symtab(struct module *mod, struct load_info *info)
2231 Elf_Shdr *symsect = info->sechdrs + info->index.sym;
2232 Elf_Shdr *strsect = info->sechdrs + info->index.str;
2233 const Elf_Sym *src;
2234 unsigned int i, nsrc, ndst, strtab_size;
2236 /* Put symbol section at end of init part of module. */
2237 symsect->sh_flags |= SHF_ALLOC;
2238 symsect->sh_entsize = get_offset(mod, &mod->init_size, symsect,
2239 info->index.sym) | INIT_OFFSET_MASK;
2240 pr_debug("\t%s\n", info->secstrings + symsect->sh_name);
2242 src = (void *)info->hdr + symsect->sh_offset;
2243 nsrc = symsect->sh_size / sizeof(*src);
2245 /* Compute total space required for the core symbols' strtab. */
2246 for (ndst = i = strtab_size = 1; i < nsrc; ++i, ++src)
2247 if (is_core_symbol(src, info->sechdrs, info->hdr->e_shnum)) {
2248 strtab_size += strlen(&info->strtab[src->st_name]) + 1;
2249 ndst++;
2252 /* Append room for core symbols at end of core part. */
2253 info->symoffs = ALIGN(mod->core_size, symsect->sh_addralign ?: 1);
2254 info->stroffs = mod->core_size = info->symoffs + ndst * sizeof(Elf_Sym);
2255 mod->core_size += strtab_size;
2257 /* Put string table section at end of init part of module. */
2258 strsect->sh_flags |= SHF_ALLOC;
2259 strsect->sh_entsize = get_offset(mod, &mod->init_size, strsect,
2260 info->index.str) | INIT_OFFSET_MASK;
2261 pr_debug("\t%s\n", info->secstrings + strsect->sh_name);
2264 static void add_kallsyms(struct module *mod, const struct load_info *info)
2266 unsigned int i, ndst;
2267 const Elf_Sym *src;
2268 Elf_Sym *dst;
2269 char *s;
2270 Elf_Shdr *symsec = &info->sechdrs[info->index.sym];
2272 mod->symtab = (void *)symsec->sh_addr;
2273 mod->num_symtab = symsec->sh_size / sizeof(Elf_Sym);
2274 /* Make sure we get permanent strtab: don't use info->strtab. */
2275 mod->strtab = (void *)info->sechdrs[info->index.str].sh_addr;
2277 /* Set types up while we still have access to sections. */
2278 for (i = 0; i < mod->num_symtab; i++)
2279 mod->symtab[i].st_info = elf_type(&mod->symtab[i], info);
2281 mod->core_symtab = dst = mod->module_core + info->symoffs;
2282 mod->core_strtab = s = mod->module_core + info->stroffs;
2283 src = mod->symtab;
2284 *dst = *src;
2285 *s++ = 0;
2286 for (ndst = i = 1; i < mod->num_symtab; ++i, ++src) {
2287 if (!is_core_symbol(src, info->sechdrs, info->hdr->e_shnum))
2288 continue;
2290 dst[ndst] = *src;
2291 dst[ndst++].st_name = s - mod->core_strtab;
2292 s += strlcpy(s, &mod->strtab[src->st_name], KSYM_NAME_LEN) + 1;
2294 mod->core_num_syms = ndst;
2296 #else
2297 static inline void layout_symtab(struct module *mod, struct load_info *info)
2301 static void add_kallsyms(struct module *mod, const struct load_info *info)
2304 #endif /* CONFIG_KALLSYMS */
2306 static void dynamic_debug_setup(struct _ddebug *debug, unsigned int num)
2308 if (!debug)
2309 return;
2310 #ifdef CONFIG_DYNAMIC_DEBUG
2311 if (ddebug_add_module(debug, num, debug->modname))
2312 printk(KERN_ERR "dynamic debug error adding module: %s\n",
2313 debug->modname);
2314 #endif
2317 static void dynamic_debug_remove(struct _ddebug *debug)
2319 if (debug)
2320 ddebug_remove_module(debug->modname);
2323 void * __weak module_alloc(unsigned long size)
2325 return size == 0 ? NULL : vmalloc_exec(size);
2328 static void *module_alloc_update_bounds(unsigned long size)
2330 void *ret = module_alloc(size);
2332 if (ret) {
2333 mutex_lock(&module_mutex);
2334 /* Update module bounds. */
2335 if ((unsigned long)ret < module_addr_min)
2336 module_addr_min = (unsigned long)ret;
2337 if ((unsigned long)ret + size > module_addr_max)
2338 module_addr_max = (unsigned long)ret + size;
2339 mutex_unlock(&module_mutex);
2341 return ret;
2344 #ifdef CONFIG_DEBUG_KMEMLEAK
2345 static void kmemleak_load_module(const struct module *mod,
2346 const struct load_info *info)
2348 unsigned int i;
2350 /* only scan the sections containing data */
2351 kmemleak_scan_area(mod, sizeof(struct module), GFP_KERNEL);
2353 for (i = 1; i < info->hdr->e_shnum; i++) {
2354 const char *name = info->secstrings + info->sechdrs[i].sh_name;
2355 if (!(info->sechdrs[i].sh_flags & SHF_ALLOC))
2356 continue;
2357 if (!strstarts(name, ".data") && !strstarts(name, ".bss"))
2358 continue;
2360 kmemleak_scan_area((void *)info->sechdrs[i].sh_addr,
2361 info->sechdrs[i].sh_size, GFP_KERNEL);
2364 #else
2365 static inline void kmemleak_load_module(const struct module *mod,
2366 const struct load_info *info)
2369 #endif
2371 /* Sets info->hdr and info->len. */
2372 static int copy_and_check(struct load_info *info,
2373 const void __user *umod, unsigned long len,
2374 const char __user *uargs)
2376 int err;
2377 Elf_Ehdr *hdr;
2379 if (len < sizeof(*hdr))
2380 return -ENOEXEC;
2382 /* Suck in entire file: we'll want most of it. */
2383 if ((hdr = vmalloc(len)) == NULL)
2384 return -ENOMEM;
2386 if (copy_from_user(hdr, umod, len) != 0) {
2387 err = -EFAULT;
2388 goto free_hdr;
2391 /* Sanity checks against insmoding binaries or wrong arch,
2392 weird elf version */
2393 if (memcmp(hdr->e_ident, ELFMAG, SELFMAG) != 0
2394 || hdr->e_type != ET_REL
2395 || !elf_check_arch(hdr)
2396 || hdr->e_shentsize != sizeof(Elf_Shdr)) {
2397 err = -ENOEXEC;
2398 goto free_hdr;
2401 if (len < hdr->e_shoff + hdr->e_shnum * sizeof(Elf_Shdr)) {
2402 err = -ENOEXEC;
2403 goto free_hdr;
2406 info->hdr = hdr;
2407 info->len = len;
2408 return 0;
2410 free_hdr:
2411 vfree(hdr);
2412 return err;
2415 static void free_copy(struct load_info *info)
2417 vfree(info->hdr);
2420 static int rewrite_section_headers(struct load_info *info)
2422 unsigned int i;
2424 /* This should always be true, but let's be sure. */
2425 info->sechdrs[0].sh_addr = 0;
2427 for (i = 1; i < info->hdr->e_shnum; i++) {
2428 Elf_Shdr *shdr = &info->sechdrs[i];
2429 if (shdr->sh_type != SHT_NOBITS
2430 && info->len < shdr->sh_offset + shdr->sh_size) {
2431 printk(KERN_ERR "Module len %lu truncated\n",
2432 info->len);
2433 return -ENOEXEC;
2436 /* Mark all sections sh_addr with their address in the
2437 temporary image. */
2438 shdr->sh_addr = (size_t)info->hdr + shdr->sh_offset;
2440 #ifndef CONFIG_MODULE_UNLOAD
2441 /* Don't load .exit sections */
2442 if (strstarts(info->secstrings+shdr->sh_name, ".exit"))
2443 shdr->sh_flags &= ~(unsigned long)SHF_ALLOC;
2444 #endif
2447 /* Track but don't keep modinfo and version sections. */
2448 info->index.vers = find_sec(info, "__versions");
2449 info->index.info = find_sec(info, ".modinfo");
2450 info->sechdrs[info->index.info].sh_flags &= ~(unsigned long)SHF_ALLOC;
2451 info->sechdrs[info->index.vers].sh_flags &= ~(unsigned long)SHF_ALLOC;
2452 return 0;
2456 * Set up our basic convenience variables (pointers to section headers,
2457 * search for module section index etc), and do some basic section
2458 * verification.
2460 * Return the temporary module pointer (we'll replace it with the final
2461 * one when we move the module sections around).
2463 static struct module *setup_load_info(struct load_info *info)
2465 unsigned int i;
2466 int err;
2467 struct module *mod;
2469 /* Set up the convenience variables */
2470 info->sechdrs = (void *)info->hdr + info->hdr->e_shoff;
2471 info->secstrings = (void *)info->hdr
2472 + info->sechdrs[info->hdr->e_shstrndx].sh_offset;
2474 err = rewrite_section_headers(info);
2475 if (err)
2476 return ERR_PTR(err);
2478 /* Find internal symbols and strings. */
2479 for (i = 1; i < info->hdr->e_shnum; i++) {
2480 if (info->sechdrs[i].sh_type == SHT_SYMTAB) {
2481 info->index.sym = i;
2482 info->index.str = info->sechdrs[i].sh_link;
2483 info->strtab = (char *)info->hdr
2484 + info->sechdrs[info->index.str].sh_offset;
2485 break;
2489 info->index.mod = find_sec(info, ".gnu.linkonce.this_module");
2490 if (!info->index.mod) {
2491 printk(KERN_WARNING "No module found in object\n");
2492 return ERR_PTR(-ENOEXEC);
2494 /* This is temporary: point mod into copy of data. */
2495 mod = (void *)info->sechdrs[info->index.mod].sh_addr;
2497 if (info->index.sym == 0) {
2498 printk(KERN_WARNING "%s: module has no symbols (stripped?)\n",
2499 mod->name);
2500 return ERR_PTR(-ENOEXEC);
2503 info->index.pcpu = find_pcpusec(info);
2505 /* Check module struct version now, before we try to use module. */
2506 if (!check_modstruct_version(info->sechdrs, info->index.vers, mod))
2507 return ERR_PTR(-ENOEXEC);
2509 return mod;
2512 static int check_modinfo(struct module *mod, struct load_info *info)
2514 const char *modmagic = get_modinfo(info, "vermagic");
2515 int err;
2517 /* This is allowed: modprobe --force will invalidate it. */
2518 if (!modmagic) {
2519 err = try_to_force_load(mod, "bad vermagic");
2520 if (err)
2521 return err;
2522 } else if (!same_magic(modmagic, vermagic, info->index.vers)) {
2523 printk(KERN_ERR "%s: version magic '%s' should be '%s'\n",
2524 mod->name, modmagic, vermagic);
2525 return -ENOEXEC;
2528 if (!get_modinfo(info, "intree"))
2529 add_taint_module(mod, TAINT_OOT_MODULE);
2531 if (get_modinfo(info, "staging")) {
2532 add_taint_module(mod, TAINT_CRAP);
2533 printk(KERN_WARNING "%s: module is from the staging directory,"
2534 " the quality is unknown, you have been warned.\n",
2535 mod->name);
2538 /* Set up license info based on the info section */
2539 set_license(mod, get_modinfo(info, "license"));
2541 return 0;
2544 static void find_module_sections(struct module *mod, struct load_info *info)
2546 mod->kp = section_objs(info, "__param",
2547 sizeof(*mod->kp), &mod->num_kp);
2548 mod->syms = section_objs(info, "__ksymtab",
2549 sizeof(*mod->syms), &mod->num_syms);
2550 mod->crcs = section_addr(info, "__kcrctab");
2551 mod->gpl_syms = section_objs(info, "__ksymtab_gpl",
2552 sizeof(*mod->gpl_syms),
2553 &mod->num_gpl_syms);
2554 mod->gpl_crcs = section_addr(info, "__kcrctab_gpl");
2555 mod->gpl_future_syms = section_objs(info,
2556 "__ksymtab_gpl_future",
2557 sizeof(*mod->gpl_future_syms),
2558 &mod->num_gpl_future_syms);
2559 mod->gpl_future_crcs = section_addr(info, "__kcrctab_gpl_future");
2561 #ifdef CONFIG_UNUSED_SYMBOLS
2562 mod->unused_syms = section_objs(info, "__ksymtab_unused",
2563 sizeof(*mod->unused_syms),
2564 &mod->num_unused_syms);
2565 mod->unused_crcs = section_addr(info, "__kcrctab_unused");
2566 mod->unused_gpl_syms = section_objs(info, "__ksymtab_unused_gpl",
2567 sizeof(*mod->unused_gpl_syms),
2568 &mod->num_unused_gpl_syms);
2569 mod->unused_gpl_crcs = section_addr(info, "__kcrctab_unused_gpl");
2570 #endif
2571 #ifdef CONFIG_CONSTRUCTORS
2572 mod->ctors = section_objs(info, ".ctors",
2573 sizeof(*mod->ctors), &mod->num_ctors);
2574 #endif
2576 #ifdef CONFIG_TRACEPOINTS
2577 mod->tracepoints_ptrs = section_objs(info, "__tracepoints_ptrs",
2578 sizeof(*mod->tracepoints_ptrs),
2579 &mod->num_tracepoints);
2580 #endif
2581 #ifdef HAVE_JUMP_LABEL
2582 mod->jump_entries = section_objs(info, "__jump_table",
2583 sizeof(*mod->jump_entries),
2584 &mod->num_jump_entries);
2585 #endif
2586 #ifdef CONFIG_EVENT_TRACING
2587 mod->trace_events = section_objs(info, "_ftrace_events",
2588 sizeof(*mod->trace_events),
2589 &mod->num_trace_events);
2591 * This section contains pointers to allocated objects in the trace
2592 * code and not scanning it leads to false positives.
2594 kmemleak_scan_area(mod->trace_events, sizeof(*mod->trace_events) *
2595 mod->num_trace_events, GFP_KERNEL);
2596 #endif
2597 #ifdef CONFIG_TRACING
2598 mod->trace_bprintk_fmt_start = section_objs(info, "__trace_printk_fmt",
2599 sizeof(*mod->trace_bprintk_fmt_start),
2600 &mod->num_trace_bprintk_fmt);
2602 * This section contains pointers to allocated objects in the trace
2603 * code and not scanning it leads to false positives.
2605 kmemleak_scan_area(mod->trace_bprintk_fmt_start,
2606 sizeof(*mod->trace_bprintk_fmt_start) *
2607 mod->num_trace_bprintk_fmt, GFP_KERNEL);
2608 #endif
2609 #ifdef CONFIG_FTRACE_MCOUNT_RECORD
2610 /* sechdrs[0].sh_size is always zero */
2611 mod->ftrace_callsites = section_objs(info, "__mcount_loc",
2612 sizeof(*mod->ftrace_callsites),
2613 &mod->num_ftrace_callsites);
2614 #endif
2616 mod->extable = section_objs(info, "__ex_table",
2617 sizeof(*mod->extable), &mod->num_exentries);
2619 if (section_addr(info, "__obsparm"))
2620 printk(KERN_WARNING "%s: Ignoring obsolete parameters\n",
2621 mod->name);
2623 info->debug = section_objs(info, "__verbose",
2624 sizeof(*info->debug), &info->num_debug);
2627 static int move_module(struct module *mod, struct load_info *info)
2629 int i;
2630 void *ptr;
2632 /* Do the allocs. */
2633 ptr = module_alloc_update_bounds(mod->core_size);
2635 * The pointer to this block is stored in the module structure
2636 * which is inside the block. Just mark it as not being a
2637 * leak.
2639 kmemleak_not_leak(ptr);
2640 if (!ptr)
2641 return -ENOMEM;
2643 memset(ptr, 0, mod->core_size);
2644 mod->module_core = ptr;
2646 ptr = module_alloc_update_bounds(mod->init_size);
2648 * The pointer to this block is stored in the module structure
2649 * which is inside the block. This block doesn't need to be
2650 * scanned as it contains data and code that will be freed
2651 * after the module is initialized.
2653 kmemleak_ignore(ptr);
2654 if (!ptr && mod->init_size) {
2655 module_free(mod, mod->module_core);
2656 return -ENOMEM;
2658 memset(ptr, 0, mod->init_size);
2659 mod->module_init = ptr;
2661 /* Transfer each section which specifies SHF_ALLOC */
2662 pr_debug("final section addresses:\n");
2663 for (i = 0; i < info->hdr->e_shnum; i++) {
2664 void *dest;
2665 Elf_Shdr *shdr = &info->sechdrs[i];
2667 if (!(shdr->sh_flags & SHF_ALLOC))
2668 continue;
2670 if (shdr->sh_entsize & INIT_OFFSET_MASK)
2671 dest = mod->module_init
2672 + (shdr->sh_entsize & ~INIT_OFFSET_MASK);
2673 else
2674 dest = mod->module_core + shdr->sh_entsize;
2676 if (shdr->sh_type != SHT_NOBITS)
2677 memcpy(dest, (void *)shdr->sh_addr, shdr->sh_size);
2678 /* Update sh_addr to point to copy in image. */
2679 shdr->sh_addr = (unsigned long)dest;
2680 pr_debug("\t0x%lx %s\n",
2681 (long)shdr->sh_addr, info->secstrings + shdr->sh_name);
2684 return 0;
2687 static int check_module_license_and_versions(struct module *mod)
2690 * ndiswrapper is under GPL by itself, but loads proprietary modules.
2691 * Don't use add_taint_module(), as it would prevent ndiswrapper from
2692 * using GPL-only symbols it needs.
2694 if (strcmp(mod->name, "ndiswrapper") == 0)
2695 add_taint(TAINT_PROPRIETARY_MODULE);
2697 /* driverloader was caught wrongly pretending to be under GPL */
2698 if (strcmp(mod->name, "driverloader") == 0)
2699 add_taint_module(mod, TAINT_PROPRIETARY_MODULE);
2701 #ifdef CONFIG_MODVERSIONS
2702 if ((mod->num_syms && !mod->crcs)
2703 || (mod->num_gpl_syms && !mod->gpl_crcs)
2704 || (mod->num_gpl_future_syms && !mod->gpl_future_crcs)
2705 #ifdef CONFIG_UNUSED_SYMBOLS
2706 || (mod->num_unused_syms && !mod->unused_crcs)
2707 || (mod->num_unused_gpl_syms && !mod->unused_gpl_crcs)
2708 #endif
2710 return try_to_force_load(mod,
2711 "no versions for exported symbols");
2713 #endif
2714 return 0;
2717 static void flush_module_icache(const struct module *mod)
2719 mm_segment_t old_fs;
2721 /* flush the icache in correct context */
2722 old_fs = get_fs();
2723 set_fs(KERNEL_DS);
2726 * Flush the instruction cache, since we've played with text.
2727 * Do it before processing of module parameters, so the module
2728 * can provide parameter accessor functions of its own.
2730 if (mod->module_init)
2731 flush_icache_range((unsigned long)mod->module_init,
2732 (unsigned long)mod->module_init
2733 + mod->init_size);
2734 flush_icache_range((unsigned long)mod->module_core,
2735 (unsigned long)mod->module_core + mod->core_size);
2737 set_fs(old_fs);
2740 int __weak module_frob_arch_sections(Elf_Ehdr *hdr,
2741 Elf_Shdr *sechdrs,
2742 char *secstrings,
2743 struct module *mod)
2745 return 0;
2748 static struct module *layout_and_allocate(struct load_info *info)
2750 /* Module within temporary copy. */
2751 struct module *mod;
2752 Elf_Shdr *pcpusec;
2753 int err;
2755 mod = setup_load_info(info);
2756 if (IS_ERR(mod))
2757 return mod;
2759 err = check_modinfo(mod, info);
2760 if (err)
2761 return ERR_PTR(err);
2763 /* Allow arches to frob section contents and sizes. */
2764 err = module_frob_arch_sections(info->hdr, info->sechdrs,
2765 info->secstrings, mod);
2766 if (err < 0)
2767 goto out;
2769 pcpusec = &info->sechdrs[info->index.pcpu];
2770 if (pcpusec->sh_size) {
2771 /* We have a special allocation for this section. */
2772 err = percpu_modalloc(mod,
2773 pcpusec->sh_size, pcpusec->sh_addralign);
2774 if (err)
2775 goto out;
2776 pcpusec->sh_flags &= ~(unsigned long)SHF_ALLOC;
2779 /* Determine total sizes, and put offsets in sh_entsize. For now
2780 this is done generically; there doesn't appear to be any
2781 special cases for the architectures. */
2782 layout_sections(mod, info);
2783 layout_symtab(mod, info);
2785 /* Allocate and move to the final place */
2786 err = move_module(mod, info);
2787 if (err)
2788 goto free_percpu;
2790 /* Module has been copied to its final place now: return it. */
2791 mod = (void *)info->sechdrs[info->index.mod].sh_addr;
2792 kmemleak_load_module(mod, info);
2793 return mod;
2795 free_percpu:
2796 percpu_modfree(mod);
2797 out:
2798 return ERR_PTR(err);
2801 /* mod is no longer valid after this! */
2802 static void module_deallocate(struct module *mod, struct load_info *info)
2804 percpu_modfree(mod);
2805 module_free(mod, mod->module_init);
2806 module_free(mod, mod->module_core);
2809 int __weak module_finalize(const Elf_Ehdr *hdr,
2810 const Elf_Shdr *sechdrs,
2811 struct module *me)
2813 return 0;
2816 static int post_relocation(struct module *mod, const struct load_info *info)
2818 /* Sort exception table now relocations are done. */
2819 sort_extable(mod->extable, mod->extable + mod->num_exentries);
2821 /* Copy relocated percpu area over. */
2822 percpu_modcopy(mod, (void *)info->sechdrs[info->index.pcpu].sh_addr,
2823 info->sechdrs[info->index.pcpu].sh_size);
2825 /* Setup kallsyms-specific fields. */
2826 add_kallsyms(mod, info);
2828 /* Arch-specific module finalizing. */
2829 return module_finalize(info->hdr, info->sechdrs, mod);
2832 /* Allocate and load the module: note that size of section 0 is always
2833 zero, and we rely on this for optional sections. */
2834 static struct module *load_module(void __user *umod,
2835 unsigned long len,
2836 const char __user *uargs)
2838 struct load_info info = { NULL, };
2839 struct module *mod;
2840 long err;
2842 pr_debug("load_module: umod=%p, len=%lu, uargs=%p\n",
2843 umod, len, uargs);
2845 /* Copy in the blobs from userspace, check they are vaguely sane. */
2846 err = copy_and_check(&info, umod, len, uargs);
2847 if (err)
2848 return ERR_PTR(err);
2850 /* Figure out module layout, and allocate all the memory. */
2851 mod = layout_and_allocate(&info);
2852 if (IS_ERR(mod)) {
2853 err = PTR_ERR(mod);
2854 goto free_copy;
2857 /* Now module is in final location, initialize linked lists, etc. */
2858 err = module_unload_init(mod);
2859 if (err)
2860 goto free_module;
2862 /* Now we've got everything in the final locations, we can
2863 * find optional sections. */
2864 find_module_sections(mod, &info);
2866 err = check_module_license_and_versions(mod);
2867 if (err)
2868 goto free_unload;
2870 /* Set up MODINFO_ATTR fields */
2871 setup_modinfo(mod, &info);
2873 /* Fix up syms, so that st_value is a pointer to location. */
2874 err = simplify_symbols(mod, &info);
2875 if (err < 0)
2876 goto free_modinfo;
2878 err = apply_relocations(mod, &info);
2879 if (err < 0)
2880 goto free_modinfo;
2882 err = post_relocation(mod, &info);
2883 if (err < 0)
2884 goto free_modinfo;
2886 flush_module_icache(mod);
2888 /* Now copy in args */
2889 mod->args = strndup_user(uargs, ~0UL >> 1);
2890 if (IS_ERR(mod->args)) {
2891 err = PTR_ERR(mod->args);
2892 goto free_arch_cleanup;
2895 /* Mark state as coming so strong_try_module_get() ignores us. */
2896 mod->state = MODULE_STATE_COMING;
2898 /* Now sew it into the lists so we can get lockdep and oops
2899 * info during argument parsing. No one should access us, since
2900 * strong_try_module_get() will fail.
2901 * lockdep/oops can run asynchronous, so use the RCU list insertion
2902 * function to insert in a way safe to concurrent readers.
2903 * The mutex protects against concurrent writers.
2905 mutex_lock(&module_mutex);
2906 if (find_module(mod->name)) {
2907 err = -EEXIST;
2908 goto unlock;
2911 /* This has to be done once we're sure module name is unique. */
2912 dynamic_debug_setup(info.debug, info.num_debug);
2914 /* Find duplicate symbols */
2915 err = verify_export_symbols(mod);
2916 if (err < 0)
2917 goto ddebug;
2919 module_bug_finalize(info.hdr, info.sechdrs, mod);
2920 list_add_rcu(&mod->list, &modules);
2921 mutex_unlock(&module_mutex);
2923 /* Module is ready to execute: parsing args may do that. */
2924 err = parse_args(mod->name, mod->args, mod->kp, mod->num_kp, NULL);
2925 if (err < 0)
2926 goto unlink;
2928 /* Link in to syfs. */
2929 err = mod_sysfs_setup(mod, &info, mod->kp, mod->num_kp);
2930 if (err < 0)
2931 goto unlink;
2933 /* Get rid of temporary copy. */
2934 free_copy(&info);
2936 /* Done! */
2937 trace_module_load(mod);
2938 return mod;
2940 unlink:
2941 mutex_lock(&module_mutex);
2942 /* Unlink carefully: kallsyms could be walking list. */
2943 list_del_rcu(&mod->list);
2944 module_bug_cleanup(mod);
2946 ddebug:
2947 dynamic_debug_remove(info.debug);
2948 unlock:
2949 mutex_unlock(&module_mutex);
2950 synchronize_sched();
2951 kfree(mod->args);
2952 free_arch_cleanup:
2953 module_arch_cleanup(mod);
2954 free_modinfo:
2955 free_modinfo(mod);
2956 free_unload:
2957 module_unload_free(mod);
2958 free_module:
2959 module_deallocate(mod, &info);
2960 free_copy:
2961 free_copy(&info);
2962 return ERR_PTR(err);
2965 /* Call module constructors. */
2966 static void do_mod_ctors(struct module *mod)
2968 #ifdef CONFIG_CONSTRUCTORS
2969 unsigned long i;
2971 for (i = 0; i < mod->num_ctors; i++)
2972 mod->ctors[i]();
2973 #endif
2976 /* This is where the real work happens */
2977 SYSCALL_DEFINE3(init_module, void __user *, umod,
2978 unsigned long, len, const char __user *, uargs)
2980 struct module *mod;
2981 int ret = 0;
2983 /* Must have permission */
2984 if (!capable(CAP_SYS_MODULE) || modules_disabled)
2985 return -EPERM;
2987 /* Do all the hard work */
2988 mod = load_module(umod, len, uargs);
2989 if (IS_ERR(mod))
2990 return PTR_ERR(mod);
2992 blocking_notifier_call_chain(&module_notify_list,
2993 MODULE_STATE_COMING, mod);
2995 /* Set RO and NX regions for core */
2996 set_section_ro_nx(mod->module_core,
2997 mod->core_text_size,
2998 mod->core_ro_size,
2999 mod->core_size);
3001 /* Set RO and NX regions for init */
3002 set_section_ro_nx(mod->module_init,
3003 mod->init_text_size,
3004 mod->init_ro_size,
3005 mod->init_size);
3007 do_mod_ctors(mod);
3008 /* Start the module */
3009 if (mod->init != NULL)
3010 ret = do_one_initcall(mod->init);
3011 if (ret < 0) {
3012 /* Init routine failed: abort. Try to protect us from
3013 buggy refcounters. */
3014 mod->state = MODULE_STATE_GOING;
3015 synchronize_sched();
3016 module_put(mod);
3017 blocking_notifier_call_chain(&module_notify_list,
3018 MODULE_STATE_GOING, mod);
3019 free_module(mod);
3020 wake_up(&module_wq);
3021 return ret;
3023 if (ret > 0) {
3024 printk(KERN_WARNING
3025 "%s: '%s'->init suspiciously returned %d, it should follow 0/-E convention\n"
3026 "%s: loading module anyway...\n",
3027 __func__, mod->name, ret,
3028 __func__);
3029 dump_stack();
3032 /* Now it's a first class citizen! Wake up anyone waiting for it. */
3033 mod->state = MODULE_STATE_LIVE;
3034 wake_up(&module_wq);
3035 blocking_notifier_call_chain(&module_notify_list,
3036 MODULE_STATE_LIVE, mod);
3038 /* We need to finish all async code before the module init sequence is done */
3039 async_synchronize_full();
3041 mutex_lock(&module_mutex);
3042 /* Drop initial reference. */
3043 module_put(mod);
3044 trim_init_extable(mod);
3045 #ifdef CONFIG_KALLSYMS
3046 mod->num_symtab = mod->core_num_syms;
3047 mod->symtab = mod->core_symtab;
3048 mod->strtab = mod->core_strtab;
3049 #endif
3050 unset_module_init_ro_nx(mod);
3051 module_free(mod, mod->module_init);
3052 mod->module_init = NULL;
3053 mod->init_size = 0;
3054 mod->init_ro_size = 0;
3055 mod->init_text_size = 0;
3056 mutex_unlock(&module_mutex);
3058 return 0;
3061 static inline int within(unsigned long addr, void *start, unsigned long size)
3063 return ((void *)addr >= start && (void *)addr < start + size);
3066 #ifdef CONFIG_KALLSYMS
3068 * This ignores the intensely annoying "mapping symbols" found
3069 * in ARM ELF files: $a, $t and $d.
3071 static inline int is_arm_mapping_symbol(const char *str)
3073 return str[0] == '$' && strchr("atd", str[1])
3074 && (str[2] == '\0' || str[2] == '.');
3077 static const char *get_ksymbol(struct module *mod,
3078 unsigned long addr,
3079 unsigned long *size,
3080 unsigned long *offset)
3082 unsigned int i, best = 0;
3083 unsigned long nextval;
3085 /* At worse, next value is at end of module */
3086 if (within_module_init(addr, mod))
3087 nextval = (unsigned long)mod->module_init+mod->init_text_size;
3088 else
3089 nextval = (unsigned long)mod->module_core+mod->core_text_size;
3091 /* Scan for closest preceding symbol, and next symbol. (ELF
3092 starts real symbols at 1). */
3093 for (i = 1; i < mod->num_symtab; i++) {
3094 if (mod->symtab[i].st_shndx == SHN_UNDEF)
3095 continue;
3097 /* We ignore unnamed symbols: they're uninformative
3098 * and inserted at a whim. */
3099 if (mod->symtab[i].st_value <= addr
3100 && mod->symtab[i].st_value > mod->symtab[best].st_value
3101 && *(mod->strtab + mod->symtab[i].st_name) != '\0'
3102 && !is_arm_mapping_symbol(mod->strtab + mod->symtab[i].st_name))
3103 best = i;
3104 if (mod->symtab[i].st_value > addr
3105 && mod->symtab[i].st_value < nextval
3106 && *(mod->strtab + mod->symtab[i].st_name) != '\0'
3107 && !is_arm_mapping_symbol(mod->strtab + mod->symtab[i].st_name))
3108 nextval = mod->symtab[i].st_value;
3111 if (!best)
3112 return NULL;
3114 if (size)
3115 *size = nextval - mod->symtab[best].st_value;
3116 if (offset)
3117 *offset = addr - mod->symtab[best].st_value;
3118 return mod->strtab + mod->symtab[best].st_name;
3121 /* For kallsyms to ask for address resolution. NULL means not found. Careful
3122 * not to lock to avoid deadlock on oopses, simply disable preemption. */
3123 const char *module_address_lookup(unsigned long addr,
3124 unsigned long *size,
3125 unsigned long *offset,
3126 char **modname,
3127 char *namebuf)
3129 struct module *mod;
3130 const char *ret = NULL;
3132 preempt_disable();
3133 list_for_each_entry_rcu(mod, &modules, list) {
3134 if (within_module_init(addr, mod) ||
3135 within_module_core(addr, mod)) {
3136 if (modname)
3137 *modname = mod->name;
3138 ret = get_ksymbol(mod, addr, size, offset);
3139 break;
3142 /* Make a copy in here where it's safe */
3143 if (ret) {
3144 strncpy(namebuf, ret, KSYM_NAME_LEN - 1);
3145 ret = namebuf;
3147 preempt_enable();
3148 return ret;
3151 int lookup_module_symbol_name(unsigned long addr, char *symname)
3153 struct module *mod;
3155 preempt_disable();
3156 list_for_each_entry_rcu(mod, &modules, list) {
3157 if (within_module_init(addr, mod) ||
3158 within_module_core(addr, mod)) {
3159 const char *sym;
3161 sym = get_ksymbol(mod, addr, NULL, NULL);
3162 if (!sym)
3163 goto out;
3164 strlcpy(symname, sym, KSYM_NAME_LEN);
3165 preempt_enable();
3166 return 0;
3169 out:
3170 preempt_enable();
3171 return -ERANGE;
3174 int lookup_module_symbol_attrs(unsigned long addr, unsigned long *size,
3175 unsigned long *offset, char *modname, char *name)
3177 struct module *mod;
3179 preempt_disable();
3180 list_for_each_entry_rcu(mod, &modules, list) {
3181 if (within_module_init(addr, mod) ||
3182 within_module_core(addr, mod)) {
3183 const char *sym;
3185 sym = get_ksymbol(mod, addr, size, offset);
3186 if (!sym)
3187 goto out;
3188 if (modname)
3189 strlcpy(modname, mod->name, MODULE_NAME_LEN);
3190 if (name)
3191 strlcpy(name, sym, KSYM_NAME_LEN);
3192 preempt_enable();
3193 return 0;
3196 out:
3197 preempt_enable();
3198 return -ERANGE;
3201 int module_get_kallsym(unsigned int symnum, unsigned long *value, char *type,
3202 char *name, char *module_name, int *exported)
3204 struct module *mod;
3206 preempt_disable();
3207 list_for_each_entry_rcu(mod, &modules, list) {
3208 if (symnum < mod->num_symtab) {
3209 *value = mod->symtab[symnum].st_value;
3210 *type = mod->symtab[symnum].st_info;
3211 strlcpy(name, mod->strtab + mod->symtab[symnum].st_name,
3212 KSYM_NAME_LEN);
3213 strlcpy(module_name, mod->name, MODULE_NAME_LEN);
3214 *exported = is_exported(name, *value, mod);
3215 preempt_enable();
3216 return 0;
3218 symnum -= mod->num_symtab;
3220 preempt_enable();
3221 return -ERANGE;
3224 static unsigned long mod_find_symname(struct module *mod, const char *name)
3226 unsigned int i;
3228 for (i = 0; i < mod->num_symtab; i++)
3229 if (strcmp(name, mod->strtab+mod->symtab[i].st_name) == 0 &&
3230 mod->symtab[i].st_info != 'U')
3231 return mod->symtab[i].st_value;
3232 return 0;
3235 /* Look for this name: can be of form module:name. */
3236 unsigned long module_kallsyms_lookup_name(const char *name)
3238 struct module *mod;
3239 char *colon;
3240 unsigned long ret = 0;
3242 /* Don't lock: we're in enough trouble already. */
3243 preempt_disable();
3244 if ((colon = strchr(name, ':')) != NULL) {
3245 *colon = '\0';
3246 if ((mod = find_module(name)) != NULL)
3247 ret = mod_find_symname(mod, colon+1);
3248 *colon = ':';
3249 } else {
3250 list_for_each_entry_rcu(mod, &modules, list)
3251 if ((ret = mod_find_symname(mod, name)) != 0)
3252 break;
3254 preempt_enable();
3255 return ret;
3258 int module_kallsyms_on_each_symbol(int (*fn)(void *, const char *,
3259 struct module *, unsigned long),
3260 void *data)
3262 struct module *mod;
3263 unsigned int i;
3264 int ret;
3266 list_for_each_entry(mod, &modules, list) {
3267 for (i = 0; i < mod->num_symtab; i++) {
3268 ret = fn(data, mod->strtab + mod->symtab[i].st_name,
3269 mod, mod->symtab[i].st_value);
3270 if (ret != 0)
3271 return ret;
3274 return 0;
3276 #endif /* CONFIG_KALLSYMS */
3278 static char *module_flags(struct module *mod, char *buf)
3280 int bx = 0;
3282 if (mod->taints ||
3283 mod->state == MODULE_STATE_GOING ||
3284 mod->state == MODULE_STATE_COMING) {
3285 buf[bx++] = '(';
3286 bx += module_flags_taint(mod, buf + bx);
3287 /* Show a - for module-is-being-unloaded */
3288 if (mod->state == MODULE_STATE_GOING)
3289 buf[bx++] = '-';
3290 /* Show a + for module-is-being-loaded */
3291 if (mod->state == MODULE_STATE_COMING)
3292 buf[bx++] = '+';
3293 buf[bx++] = ')';
3295 buf[bx] = '\0';
3297 return buf;
3300 #ifdef CONFIG_PROC_FS
3301 /* Called by the /proc file system to return a list of modules. */
3302 static void *m_start(struct seq_file *m, loff_t *pos)
3304 mutex_lock(&module_mutex);
3305 return seq_list_start(&modules, *pos);
3308 static void *m_next(struct seq_file *m, void *p, loff_t *pos)
3310 return seq_list_next(p, &modules, pos);
3313 static void m_stop(struct seq_file *m, void *p)
3315 mutex_unlock(&module_mutex);
3318 static int m_show(struct seq_file *m, void *p)
3320 struct module *mod = list_entry(p, struct module, list);
3321 char buf[8];
3323 seq_printf(m, "%s %u",
3324 mod->name, mod->init_size + mod->core_size);
3325 print_unload_info(m, mod);
3327 /* Informative for users. */
3328 seq_printf(m, " %s",
3329 mod->state == MODULE_STATE_GOING ? "Unloading":
3330 mod->state == MODULE_STATE_COMING ? "Loading":
3331 "Live");
3332 /* Used by oprofile and other similar tools. */
3333 seq_printf(m, " 0x%pK", mod->module_core);
3335 /* Taints info */
3336 if (mod->taints)
3337 seq_printf(m, " %s", module_flags(mod, buf));
3339 seq_printf(m, "\n");
3340 return 0;
3343 /* Format: modulename size refcount deps address
3345 Where refcount is a number or -, and deps is a comma-separated list
3346 of depends or -.
3348 static const struct seq_operations modules_op = {
3349 .start = m_start,
3350 .next = m_next,
3351 .stop = m_stop,
3352 .show = m_show
3355 static int modules_open(struct inode *inode, struct file *file)
3357 return seq_open(file, &modules_op);
3360 static const struct file_operations proc_modules_operations = {
3361 .open = modules_open,
3362 .read = seq_read,
3363 .llseek = seq_lseek,
3364 .release = seq_release,
3367 static int __init proc_modules_init(void)
3369 proc_create("modules", 0, NULL, &proc_modules_operations);
3370 return 0;
3372 module_init(proc_modules_init);
3373 #endif
3375 /* Given an address, look for it in the module exception tables. */
3376 const struct exception_table_entry *search_module_extables(unsigned long addr)
3378 const struct exception_table_entry *e = NULL;
3379 struct module *mod;
3381 preempt_disable();
3382 list_for_each_entry_rcu(mod, &modules, list) {
3383 if (mod->num_exentries == 0)
3384 continue;
3386 e = search_extable(mod->extable,
3387 mod->extable + mod->num_exentries - 1,
3388 addr);
3389 if (e)
3390 break;
3392 preempt_enable();
3394 /* Now, if we found one, we are running inside it now, hence
3395 we cannot unload the module, hence no refcnt needed. */
3396 return e;
3400 * is_module_address - is this address inside a module?
3401 * @addr: the address to check.
3403 * See is_module_text_address() if you simply want to see if the address
3404 * is code (not data).
3406 bool is_module_address(unsigned long addr)
3408 bool ret;
3410 preempt_disable();
3411 ret = __module_address(addr) != NULL;
3412 preempt_enable();
3414 return ret;
3418 * __module_address - get the module which contains an address.
3419 * @addr: the address.
3421 * Must be called with preempt disabled or module mutex held so that
3422 * module doesn't get freed during this.
3424 struct module *__module_address(unsigned long addr)
3426 struct module *mod;
3428 if (addr < module_addr_min || addr > module_addr_max)
3429 return NULL;
3431 list_for_each_entry_rcu(mod, &modules, list)
3432 if (within_module_core(addr, mod)
3433 || within_module_init(addr, mod))
3434 return mod;
3435 return NULL;
3437 EXPORT_SYMBOL_GPL(__module_address);
3440 * is_module_text_address - is this address inside module code?
3441 * @addr: the address to check.
3443 * See is_module_address() if you simply want to see if the address is
3444 * anywhere in a module. See kernel_text_address() for testing if an
3445 * address corresponds to kernel or module code.
3447 bool is_module_text_address(unsigned long addr)
3449 bool ret;
3451 preempt_disable();
3452 ret = __module_text_address(addr) != NULL;
3453 preempt_enable();
3455 return ret;
3459 * __module_text_address - get the module whose code contains an address.
3460 * @addr: the address.
3462 * Must be called with preempt disabled or module mutex held so that
3463 * module doesn't get freed during this.
3465 struct module *__module_text_address(unsigned long addr)
3467 struct module *mod = __module_address(addr);
3468 if (mod) {
3469 /* Make sure it's within the text section. */
3470 if (!within(addr, mod->module_init, mod->init_text_size)
3471 && !within(addr, mod->module_core, mod->core_text_size))
3472 mod = NULL;
3474 return mod;
3476 EXPORT_SYMBOL_GPL(__module_text_address);
3478 /* Don't grab lock, we're oopsing. */
3479 void print_modules(void)
3481 struct module *mod;
3482 char buf[8];
3484 printk(KERN_DEFAULT "Modules linked in:");
3485 /* Most callers should already have preempt disabled, but make sure */
3486 preempt_disable();
3487 list_for_each_entry_rcu(mod, &modules, list)
3488 printk(" %s%s", mod->name, module_flags(mod, buf));
3489 preempt_enable();
3490 if (last_unloaded_module[0])
3491 printk(" [last unloaded: %s]", last_unloaded_module);
3492 printk("\n");
3495 #ifdef CONFIG_MODVERSIONS
3496 /* Generate the signature for all relevant module structures here.
3497 * If these change, we don't want to try to parse the module. */
3498 void module_layout(struct module *mod,
3499 struct modversion_info *ver,
3500 struct kernel_param *kp,
3501 struct kernel_symbol *ks,
3502 struct tracepoint * const *tp)
3505 EXPORT_SYMBOL(module_layout);
3506 #endif