cifs: fix oops while traversing open file list (try #4)
[linux-2.6/linux-acpi-2.6/ibm-acpi-2.6.git] / kernel / module.c
blobb9d0667efe62aece8fe10d04bcf8a5df7d8947e1
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/module.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 #if 0
66 #define DEBUGP printk
67 #else
68 #define DEBUGP(fmt , a...)
69 #endif
71 #ifndef ARCH_SHF_SMALL
72 #define ARCH_SHF_SMALL 0
73 #endif
76 * Modules' sections will be aligned on page boundaries
77 * to ensure complete separation of code and data, but
78 * only when CONFIG_DEBUG_SET_MODULE_RONX=y
80 #ifdef CONFIG_DEBUG_SET_MODULE_RONX
81 # define debug_align(X) ALIGN(X, PAGE_SIZE)
82 #else
83 # define debug_align(X) (X)
84 #endif
87 * Given BASE and SIZE this macro calculates the number of pages the
88 * memory regions occupies
90 #define MOD_NUMBER_OF_PAGES(BASE, SIZE) (((SIZE) > 0) ? \
91 (PFN_DOWN((unsigned long)(BASE) + (SIZE) - 1) - \
92 PFN_DOWN((unsigned long)BASE) + 1) \
93 : (0UL))
95 /* If this is set, the section belongs in the init part of the module */
96 #define INIT_OFFSET_MASK (1UL << (BITS_PER_LONG-1))
99 * Mutex protects:
100 * 1) List of modules (also safely readable with preempt_disable),
101 * 2) module_use links,
102 * 3) module_addr_min/module_addr_max.
103 * (delete uses stop_machine/add uses RCU list operations). */
104 DEFINE_MUTEX(module_mutex);
105 EXPORT_SYMBOL_GPL(module_mutex);
106 static LIST_HEAD(modules);
107 #ifdef CONFIG_KGDB_KDB
108 struct list_head *kdb_modules = &modules; /* kdb needs the list of modules */
109 #endif /* CONFIG_KGDB_KDB */
112 /* Block module loading/unloading? */
113 int modules_disabled = 0;
115 /* Waiting for a module to finish initializing? */
116 static DECLARE_WAIT_QUEUE_HEAD(module_wq);
118 static BLOCKING_NOTIFIER_HEAD(module_notify_list);
120 /* Bounds of module allocation, for speeding __module_address.
121 * Protected by module_mutex. */
122 static unsigned long module_addr_min = -1UL, module_addr_max = 0;
124 int register_module_notifier(struct notifier_block * nb)
126 return blocking_notifier_chain_register(&module_notify_list, nb);
128 EXPORT_SYMBOL(register_module_notifier);
130 int unregister_module_notifier(struct notifier_block * nb)
132 return blocking_notifier_chain_unregister(&module_notify_list, nb);
134 EXPORT_SYMBOL(unregister_module_notifier);
136 struct load_info {
137 Elf_Ehdr *hdr;
138 unsigned long len;
139 Elf_Shdr *sechdrs;
140 char *secstrings, *strtab;
141 unsigned long *strmap;
142 unsigned long symoffs, stroffs;
143 struct _ddebug *debug;
144 unsigned int num_debug;
145 struct {
146 unsigned int sym, str, mod, vers, info, pcpu;
147 } index;
150 /* We require a truly strong try_module_get(): 0 means failure due to
151 ongoing or failed initialization etc. */
152 static inline int strong_try_module_get(struct module *mod)
154 if (mod && mod->state == MODULE_STATE_COMING)
155 return -EBUSY;
156 if (try_module_get(mod))
157 return 0;
158 else
159 return -ENOENT;
162 static inline void add_taint_module(struct module *mod, unsigned flag)
164 add_taint(flag);
165 mod->taints |= (1U << flag);
169 * A thread that wants to hold a reference to a module only while it
170 * is running can call this to safely exit. nfsd and lockd use this.
172 void __module_put_and_exit(struct module *mod, long code)
174 module_put(mod);
175 do_exit(code);
177 EXPORT_SYMBOL(__module_put_and_exit);
179 /* Find a module section: 0 means not found. */
180 static unsigned int find_sec(const struct load_info *info, const char *name)
182 unsigned int i;
184 for (i = 1; i < info->hdr->e_shnum; i++) {
185 Elf_Shdr *shdr = &info->sechdrs[i];
186 /* Alloc bit cleared means "ignore it." */
187 if ((shdr->sh_flags & SHF_ALLOC)
188 && strcmp(info->secstrings + shdr->sh_name, name) == 0)
189 return i;
191 return 0;
194 /* Find a module section, or NULL. */
195 static void *section_addr(const struct load_info *info, const char *name)
197 /* Section 0 has sh_addr 0. */
198 return (void *)info->sechdrs[find_sec(info, name)].sh_addr;
201 /* Find a module section, or NULL. Fill in number of "objects" in section. */
202 static void *section_objs(const struct load_info *info,
203 const char *name,
204 size_t object_size,
205 unsigned int *num)
207 unsigned int sec = find_sec(info, name);
209 /* Section 0 has sh_addr 0 and sh_size 0. */
210 *num = info->sechdrs[sec].sh_size / object_size;
211 return (void *)info->sechdrs[sec].sh_addr;
214 /* Provided by the linker */
215 extern const struct kernel_symbol __start___ksymtab[];
216 extern const struct kernel_symbol __stop___ksymtab[];
217 extern const struct kernel_symbol __start___ksymtab_gpl[];
218 extern const struct kernel_symbol __stop___ksymtab_gpl[];
219 extern const struct kernel_symbol __start___ksymtab_gpl_future[];
220 extern const struct kernel_symbol __stop___ksymtab_gpl_future[];
221 extern const unsigned long __start___kcrctab[];
222 extern const unsigned long __start___kcrctab_gpl[];
223 extern const unsigned long __start___kcrctab_gpl_future[];
224 #ifdef CONFIG_UNUSED_SYMBOLS
225 extern const struct kernel_symbol __start___ksymtab_unused[];
226 extern const struct kernel_symbol __stop___ksymtab_unused[];
227 extern const struct kernel_symbol __start___ksymtab_unused_gpl[];
228 extern const struct kernel_symbol __stop___ksymtab_unused_gpl[];
229 extern const unsigned long __start___kcrctab_unused[];
230 extern const unsigned long __start___kcrctab_unused_gpl[];
231 #endif
233 #ifndef CONFIG_MODVERSIONS
234 #define symversion(base, idx) NULL
235 #else
236 #define symversion(base, idx) ((base != NULL) ? ((base) + (idx)) : NULL)
237 #endif
239 static bool each_symbol_in_section(const struct symsearch *arr,
240 unsigned int arrsize,
241 struct module *owner,
242 bool (*fn)(const struct symsearch *syms,
243 struct module *owner,
244 void *data),
245 void *data)
247 unsigned int j;
249 for (j = 0; j < arrsize; j++) {
250 if (fn(&arr[j], owner, data))
251 return true;
254 return false;
257 /* Returns true as soon as fn returns true, otherwise false. */
258 bool each_symbol_section(bool (*fn)(const struct symsearch *arr,
259 struct module *owner,
260 void *data),
261 void *data)
263 struct module *mod;
264 static const struct symsearch arr[] = {
265 { __start___ksymtab, __stop___ksymtab, __start___kcrctab,
266 NOT_GPL_ONLY, false },
267 { __start___ksymtab_gpl, __stop___ksymtab_gpl,
268 __start___kcrctab_gpl,
269 GPL_ONLY, false },
270 { __start___ksymtab_gpl_future, __stop___ksymtab_gpl_future,
271 __start___kcrctab_gpl_future,
272 WILL_BE_GPL_ONLY, false },
273 #ifdef CONFIG_UNUSED_SYMBOLS
274 { __start___ksymtab_unused, __stop___ksymtab_unused,
275 __start___kcrctab_unused,
276 NOT_GPL_ONLY, true },
277 { __start___ksymtab_unused_gpl, __stop___ksymtab_unused_gpl,
278 __start___kcrctab_unused_gpl,
279 GPL_ONLY, true },
280 #endif
283 if (each_symbol_in_section(arr, ARRAY_SIZE(arr), NULL, fn, data))
284 return true;
286 list_for_each_entry_rcu(mod, &modules, list) {
287 struct symsearch arr[] = {
288 { mod->syms, mod->syms + mod->num_syms, mod->crcs,
289 NOT_GPL_ONLY, false },
290 { mod->gpl_syms, mod->gpl_syms + mod->num_gpl_syms,
291 mod->gpl_crcs,
292 GPL_ONLY, false },
293 { mod->gpl_future_syms,
294 mod->gpl_future_syms + mod->num_gpl_future_syms,
295 mod->gpl_future_crcs,
296 WILL_BE_GPL_ONLY, false },
297 #ifdef CONFIG_UNUSED_SYMBOLS
298 { mod->unused_syms,
299 mod->unused_syms + mod->num_unused_syms,
300 mod->unused_crcs,
301 NOT_GPL_ONLY, true },
302 { mod->unused_gpl_syms,
303 mod->unused_gpl_syms + mod->num_unused_gpl_syms,
304 mod->unused_gpl_crcs,
305 GPL_ONLY, true },
306 #endif
309 if (each_symbol_in_section(arr, ARRAY_SIZE(arr), mod, fn, data))
310 return true;
312 return false;
314 EXPORT_SYMBOL_GPL(each_symbol_section);
316 struct find_symbol_arg {
317 /* Input */
318 const char *name;
319 bool gplok;
320 bool warn;
322 /* Output */
323 struct module *owner;
324 const unsigned long *crc;
325 const struct kernel_symbol *sym;
328 static bool check_symbol(const struct symsearch *syms,
329 struct module *owner,
330 unsigned int symnum, void *data)
332 struct find_symbol_arg *fsa = data;
334 if (!fsa->gplok) {
335 if (syms->licence == GPL_ONLY)
336 return false;
337 if (syms->licence == WILL_BE_GPL_ONLY && fsa->warn) {
338 printk(KERN_WARNING "Symbol %s is being used "
339 "by a non-GPL module, which will not "
340 "be allowed in the future\n", fsa->name);
341 printk(KERN_WARNING "Please see the file "
342 "Documentation/feature-removal-schedule.txt "
343 "in the kernel source tree for more details.\n");
347 #ifdef CONFIG_UNUSED_SYMBOLS
348 if (syms->unused && fsa->warn) {
349 printk(KERN_WARNING "Symbol %s is marked as UNUSED, "
350 "however this module is using it.\n", fsa->name);
351 printk(KERN_WARNING
352 "This symbol will go away in the future.\n");
353 printk(KERN_WARNING
354 "Please evalute if this is the right api to use and if "
355 "it really is, submit a report the linux kernel "
356 "mailinglist together with submitting your code for "
357 "inclusion.\n");
359 #endif
361 fsa->owner = owner;
362 fsa->crc = symversion(syms->crcs, symnum);
363 fsa->sym = &syms->start[symnum];
364 return true;
367 static int cmp_name(const void *va, const void *vb)
369 const char *a;
370 const struct kernel_symbol *b;
371 a = va; b = vb;
372 return strcmp(a, b->name);
375 static bool find_symbol_in_section(const struct symsearch *syms,
376 struct module *owner,
377 void *data)
379 struct find_symbol_arg *fsa = data;
380 struct kernel_symbol *sym;
382 sym = bsearch(fsa->name, syms->start, syms->stop - syms->start,
383 sizeof(struct kernel_symbol), cmp_name);
385 if (sym != NULL && check_symbol(syms, owner, sym - syms->start, data))
386 return true;
388 return false;
391 /* Find a symbol and return it, along with, (optional) crc and
392 * (optional) module which owns it. Needs preempt disabled or module_mutex. */
393 const struct kernel_symbol *find_symbol(const char *name,
394 struct module **owner,
395 const unsigned long **crc,
396 bool gplok,
397 bool warn)
399 struct find_symbol_arg fsa;
401 fsa.name = name;
402 fsa.gplok = gplok;
403 fsa.warn = warn;
405 if (each_symbol_section(find_symbol_in_section, &fsa)) {
406 if (owner)
407 *owner = fsa.owner;
408 if (crc)
409 *crc = fsa.crc;
410 return fsa.sym;
413 DEBUGP("Failed to find symbol %s\n", name);
414 return NULL;
416 EXPORT_SYMBOL_GPL(find_symbol);
418 /* Search for module by name: must hold module_mutex. */
419 struct module *find_module(const char *name)
421 struct module *mod;
423 list_for_each_entry(mod, &modules, list) {
424 if (strcmp(mod->name, name) == 0)
425 return mod;
427 return NULL;
429 EXPORT_SYMBOL_GPL(find_module);
431 #ifdef CONFIG_SMP
433 static inline void __percpu *mod_percpu(struct module *mod)
435 return mod->percpu;
438 static int percpu_modalloc(struct module *mod,
439 unsigned long size, unsigned long align)
441 if (align > PAGE_SIZE) {
442 printk(KERN_WARNING "%s: per-cpu alignment %li > %li\n",
443 mod->name, align, PAGE_SIZE);
444 align = PAGE_SIZE;
447 mod->percpu = __alloc_reserved_percpu(size, align);
448 if (!mod->percpu) {
449 printk(KERN_WARNING
450 "%s: Could not allocate %lu bytes percpu data\n",
451 mod->name, size);
452 return -ENOMEM;
454 mod->percpu_size = size;
455 return 0;
458 static void percpu_modfree(struct module *mod)
460 free_percpu(mod->percpu);
463 static unsigned int find_pcpusec(struct load_info *info)
465 return find_sec(info, ".data..percpu");
468 static void percpu_modcopy(struct module *mod,
469 const void *from, unsigned long size)
471 int cpu;
473 for_each_possible_cpu(cpu)
474 memcpy(per_cpu_ptr(mod->percpu, cpu), from, size);
478 * is_module_percpu_address - test whether address is from module static percpu
479 * @addr: address to test
481 * Test whether @addr belongs to module static percpu area.
483 * RETURNS:
484 * %true if @addr is from module static percpu area
486 bool is_module_percpu_address(unsigned long addr)
488 struct module *mod;
489 unsigned int cpu;
491 preempt_disable();
493 list_for_each_entry_rcu(mod, &modules, list) {
494 if (!mod->percpu_size)
495 continue;
496 for_each_possible_cpu(cpu) {
497 void *start = per_cpu_ptr(mod->percpu, cpu);
499 if ((void *)addr >= start &&
500 (void *)addr < start + mod->percpu_size) {
501 preempt_enable();
502 return true;
507 preempt_enable();
508 return false;
511 #else /* ... !CONFIG_SMP */
513 static inline void __percpu *mod_percpu(struct module *mod)
515 return NULL;
517 static inline int percpu_modalloc(struct module *mod,
518 unsigned long size, unsigned long align)
520 return -ENOMEM;
522 static inline void percpu_modfree(struct module *mod)
525 static unsigned int find_pcpusec(struct load_info *info)
527 return 0;
529 static inline void percpu_modcopy(struct module *mod,
530 const void *from, unsigned long size)
532 /* pcpusec should be 0, and size of that section should be 0. */
533 BUG_ON(size != 0);
535 bool is_module_percpu_address(unsigned long addr)
537 return false;
540 #endif /* CONFIG_SMP */
542 #define MODINFO_ATTR(field) \
543 static void setup_modinfo_##field(struct module *mod, const char *s) \
545 mod->field = kstrdup(s, GFP_KERNEL); \
547 static ssize_t show_modinfo_##field(struct module_attribute *mattr, \
548 struct module *mod, char *buffer) \
550 return sprintf(buffer, "%s\n", mod->field); \
552 static int modinfo_##field##_exists(struct module *mod) \
554 return mod->field != NULL; \
556 static void free_modinfo_##field(struct module *mod) \
558 kfree(mod->field); \
559 mod->field = NULL; \
561 static struct module_attribute modinfo_##field = { \
562 .attr = { .name = __stringify(field), .mode = 0444 }, \
563 .show = show_modinfo_##field, \
564 .setup = setup_modinfo_##field, \
565 .test = modinfo_##field##_exists, \
566 .free = free_modinfo_##field, \
569 MODINFO_ATTR(version);
570 MODINFO_ATTR(srcversion);
572 static char last_unloaded_module[MODULE_NAME_LEN+1];
574 #ifdef CONFIG_MODULE_UNLOAD
576 EXPORT_TRACEPOINT_SYMBOL(module_get);
578 /* Init the unload section of the module. */
579 static int module_unload_init(struct module *mod)
581 mod->refptr = alloc_percpu(struct module_ref);
582 if (!mod->refptr)
583 return -ENOMEM;
585 INIT_LIST_HEAD(&mod->source_list);
586 INIT_LIST_HEAD(&mod->target_list);
588 /* Hold reference count during initialization. */
589 __this_cpu_write(mod->refptr->incs, 1);
590 /* Backwards compatibility macros put refcount during init. */
591 mod->waiter = current;
593 return 0;
596 /* Does a already use b? */
597 static int already_uses(struct module *a, struct module *b)
599 struct module_use *use;
601 list_for_each_entry(use, &b->source_list, source_list) {
602 if (use->source == a) {
603 DEBUGP("%s uses %s!\n", a->name, b->name);
604 return 1;
607 DEBUGP("%s does not use %s!\n", a->name, b->name);
608 return 0;
612 * Module a uses b
613 * - we add 'a' as a "source", 'b' as a "target" of module use
614 * - the module_use is added to the list of 'b' sources (so
615 * 'b' can walk the list to see who sourced them), and of 'a'
616 * targets (so 'a' can see what modules it targets).
618 static int add_module_usage(struct module *a, struct module *b)
620 struct module_use *use;
622 DEBUGP("Allocating new usage for %s.\n", a->name);
623 use = kmalloc(sizeof(*use), GFP_ATOMIC);
624 if (!use) {
625 printk(KERN_WARNING "%s: out of memory loading\n", a->name);
626 return -ENOMEM;
629 use->source = a;
630 use->target = b;
631 list_add(&use->source_list, &b->source_list);
632 list_add(&use->target_list, &a->target_list);
633 return 0;
636 /* Module a uses b: caller needs module_mutex() */
637 int ref_module(struct module *a, struct module *b)
639 int err;
641 if (b == NULL || already_uses(a, b))
642 return 0;
644 /* If module isn't available, we fail. */
645 err = strong_try_module_get(b);
646 if (err)
647 return err;
649 err = add_module_usage(a, b);
650 if (err) {
651 module_put(b);
652 return err;
654 return 0;
656 EXPORT_SYMBOL_GPL(ref_module);
658 /* Clear the unload stuff of the module. */
659 static void module_unload_free(struct module *mod)
661 struct module_use *use, *tmp;
663 mutex_lock(&module_mutex);
664 list_for_each_entry_safe(use, tmp, &mod->target_list, target_list) {
665 struct module *i = use->target;
666 DEBUGP("%s unusing %s\n", mod->name, i->name);
667 module_put(i);
668 list_del(&use->source_list);
669 list_del(&use->target_list);
670 kfree(use);
672 mutex_unlock(&module_mutex);
674 free_percpu(mod->refptr);
677 #ifdef CONFIG_MODULE_FORCE_UNLOAD
678 static inline int try_force_unload(unsigned int flags)
680 int ret = (flags & O_TRUNC);
681 if (ret)
682 add_taint(TAINT_FORCED_RMMOD);
683 return ret;
685 #else
686 static inline int try_force_unload(unsigned int flags)
688 return 0;
690 #endif /* CONFIG_MODULE_FORCE_UNLOAD */
692 struct stopref
694 struct module *mod;
695 int flags;
696 int *forced;
699 /* Whole machine is stopped with interrupts off when this runs. */
700 static int __try_stop_module(void *_sref)
702 struct stopref *sref = _sref;
704 /* If it's not unused, quit unless we're forcing. */
705 if (module_refcount(sref->mod) != 0) {
706 if (!(*sref->forced = try_force_unload(sref->flags)))
707 return -EWOULDBLOCK;
710 /* Mark it as dying. */
711 sref->mod->state = MODULE_STATE_GOING;
712 return 0;
715 static int try_stop_module(struct module *mod, int flags, int *forced)
717 if (flags & O_NONBLOCK) {
718 struct stopref sref = { mod, flags, forced };
720 return stop_machine(__try_stop_module, &sref, NULL);
721 } else {
722 /* We don't need to stop the machine for this. */
723 mod->state = MODULE_STATE_GOING;
724 synchronize_sched();
725 return 0;
729 unsigned int module_refcount(struct module *mod)
731 unsigned int incs = 0, decs = 0;
732 int cpu;
734 for_each_possible_cpu(cpu)
735 decs += per_cpu_ptr(mod->refptr, cpu)->decs;
737 * ensure the incs are added up after the decs.
738 * module_put ensures incs are visible before decs with smp_wmb.
740 * This 2-count scheme avoids the situation where the refcount
741 * for CPU0 is read, then CPU0 increments the module refcount,
742 * then CPU1 drops that refcount, then the refcount for CPU1 is
743 * read. We would record a decrement but not its corresponding
744 * increment so we would see a low count (disaster).
746 * Rare situation? But module_refcount can be preempted, and we
747 * might be tallying up 4096+ CPUs. So it is not impossible.
749 smp_rmb();
750 for_each_possible_cpu(cpu)
751 incs += per_cpu_ptr(mod->refptr, cpu)->incs;
752 return incs - decs;
754 EXPORT_SYMBOL(module_refcount);
756 /* This exists whether we can unload or not */
757 static void free_module(struct module *mod);
759 static void wait_for_zero_refcount(struct module *mod)
761 /* Since we might sleep for some time, release the mutex first */
762 mutex_unlock(&module_mutex);
763 for (;;) {
764 DEBUGP("Looking at refcount...\n");
765 set_current_state(TASK_UNINTERRUPTIBLE);
766 if (module_refcount(mod) == 0)
767 break;
768 schedule();
770 current->state = TASK_RUNNING;
771 mutex_lock(&module_mutex);
774 SYSCALL_DEFINE2(delete_module, const char __user *, name_user,
775 unsigned int, flags)
777 struct module *mod;
778 char name[MODULE_NAME_LEN];
779 int ret, forced = 0;
781 if (!capable(CAP_SYS_MODULE) || modules_disabled)
782 return -EPERM;
784 if (strncpy_from_user(name, name_user, MODULE_NAME_LEN-1) < 0)
785 return -EFAULT;
786 name[MODULE_NAME_LEN-1] = '\0';
788 if (mutex_lock_interruptible(&module_mutex) != 0)
789 return -EINTR;
791 mod = find_module(name);
792 if (!mod) {
793 ret = -ENOENT;
794 goto out;
797 if (!list_empty(&mod->source_list)) {
798 /* Other modules depend on us: get rid of them first. */
799 ret = -EWOULDBLOCK;
800 goto out;
803 /* Doing init or already dying? */
804 if (mod->state != MODULE_STATE_LIVE) {
805 /* FIXME: if (force), slam module count and wake up
806 waiter --RR */
807 DEBUGP("%s already dying\n", mod->name);
808 ret = -EBUSY;
809 goto out;
812 /* If it has an init func, it must have an exit func to unload */
813 if (mod->init && !mod->exit) {
814 forced = try_force_unload(flags);
815 if (!forced) {
816 /* This module can't be removed */
817 ret = -EBUSY;
818 goto out;
822 /* Set this up before setting mod->state */
823 mod->waiter = current;
825 /* Stop the machine so refcounts can't move and disable module. */
826 ret = try_stop_module(mod, flags, &forced);
827 if (ret != 0)
828 goto out;
830 /* Never wait if forced. */
831 if (!forced && module_refcount(mod) != 0)
832 wait_for_zero_refcount(mod);
834 mutex_unlock(&module_mutex);
835 /* Final destruction now no one is using it. */
836 if (mod->exit != NULL)
837 mod->exit();
838 blocking_notifier_call_chain(&module_notify_list,
839 MODULE_STATE_GOING, mod);
840 async_synchronize_full();
842 /* Store the name of the last unloaded module for diagnostic purposes */
843 strlcpy(last_unloaded_module, mod->name, sizeof(last_unloaded_module));
845 free_module(mod);
846 return 0;
847 out:
848 mutex_unlock(&module_mutex);
849 return ret;
852 static inline void print_unload_info(struct seq_file *m, struct module *mod)
854 struct module_use *use;
855 int printed_something = 0;
857 seq_printf(m, " %u ", module_refcount(mod));
859 /* Always include a trailing , so userspace can differentiate
860 between this and the old multi-field proc format. */
861 list_for_each_entry(use, &mod->source_list, source_list) {
862 printed_something = 1;
863 seq_printf(m, "%s,", use->source->name);
866 if (mod->init != NULL && mod->exit == NULL) {
867 printed_something = 1;
868 seq_printf(m, "[permanent],");
871 if (!printed_something)
872 seq_printf(m, "-");
875 void __symbol_put(const char *symbol)
877 struct module *owner;
879 preempt_disable();
880 if (!find_symbol(symbol, &owner, NULL, true, false))
881 BUG();
882 module_put(owner);
883 preempt_enable();
885 EXPORT_SYMBOL(__symbol_put);
887 /* Note this assumes addr is a function, which it currently always is. */
888 void symbol_put_addr(void *addr)
890 struct module *modaddr;
891 unsigned long a = (unsigned long)dereference_function_descriptor(addr);
893 if (core_kernel_text(a))
894 return;
896 /* module_text_address is safe here: we're supposed to have reference
897 * to module from symbol_get, so it can't go away. */
898 modaddr = __module_text_address(a);
899 BUG_ON(!modaddr);
900 module_put(modaddr);
902 EXPORT_SYMBOL_GPL(symbol_put_addr);
904 static ssize_t show_refcnt(struct module_attribute *mattr,
905 struct module *mod, char *buffer)
907 return sprintf(buffer, "%u\n", module_refcount(mod));
910 static struct module_attribute refcnt = {
911 .attr = { .name = "refcnt", .mode = 0444 },
912 .show = show_refcnt,
915 void module_put(struct module *module)
917 if (module) {
918 preempt_disable();
919 smp_wmb(); /* see comment in module_refcount */
920 __this_cpu_inc(module->refptr->decs);
922 trace_module_put(module, _RET_IP_);
923 /* Maybe they're waiting for us to drop reference? */
924 if (unlikely(!module_is_live(module)))
925 wake_up_process(module->waiter);
926 preempt_enable();
929 EXPORT_SYMBOL(module_put);
931 #else /* !CONFIG_MODULE_UNLOAD */
932 static inline void print_unload_info(struct seq_file *m, struct module *mod)
934 /* We don't know the usage count, or what modules are using. */
935 seq_printf(m, " - -");
938 static inline void module_unload_free(struct module *mod)
942 int ref_module(struct module *a, struct module *b)
944 return strong_try_module_get(b);
946 EXPORT_SYMBOL_GPL(ref_module);
948 static inline int module_unload_init(struct module *mod)
950 return 0;
952 #endif /* CONFIG_MODULE_UNLOAD */
954 static ssize_t show_initstate(struct module_attribute *mattr,
955 struct module *mod, char *buffer)
957 const char *state = "unknown";
959 switch (mod->state) {
960 case MODULE_STATE_LIVE:
961 state = "live";
962 break;
963 case MODULE_STATE_COMING:
964 state = "coming";
965 break;
966 case MODULE_STATE_GOING:
967 state = "going";
968 break;
970 return sprintf(buffer, "%s\n", state);
973 static struct module_attribute initstate = {
974 .attr = { .name = "initstate", .mode = 0444 },
975 .show = show_initstate,
978 static struct module_attribute *modinfo_attrs[] = {
979 &modinfo_version,
980 &modinfo_srcversion,
981 &initstate,
982 #ifdef CONFIG_MODULE_UNLOAD
983 &refcnt,
984 #endif
985 NULL,
988 static const char vermagic[] = VERMAGIC_STRING;
990 static int try_to_force_load(struct module *mod, const char *reason)
992 #ifdef CONFIG_MODULE_FORCE_LOAD
993 if (!test_taint(TAINT_FORCED_MODULE))
994 printk(KERN_WARNING "%s: %s: kernel tainted.\n",
995 mod->name, reason);
996 add_taint_module(mod, TAINT_FORCED_MODULE);
997 return 0;
998 #else
999 return -ENOEXEC;
1000 #endif
1003 #ifdef CONFIG_MODVERSIONS
1004 /* If the arch applies (non-zero) relocations to kernel kcrctab, unapply it. */
1005 static unsigned long maybe_relocated(unsigned long crc,
1006 const struct module *crc_owner)
1008 #ifdef ARCH_RELOCATES_KCRCTAB
1009 if (crc_owner == NULL)
1010 return crc - (unsigned long)reloc_start;
1011 #endif
1012 return crc;
1015 static int check_version(Elf_Shdr *sechdrs,
1016 unsigned int versindex,
1017 const char *symname,
1018 struct module *mod,
1019 const unsigned long *crc,
1020 const struct module *crc_owner)
1022 unsigned int i, num_versions;
1023 struct modversion_info *versions;
1025 /* Exporting module didn't supply crcs? OK, we're already tainted. */
1026 if (!crc)
1027 return 1;
1029 /* No versions at all? modprobe --force does this. */
1030 if (versindex == 0)
1031 return try_to_force_load(mod, symname) == 0;
1033 versions = (void *) sechdrs[versindex].sh_addr;
1034 num_versions = sechdrs[versindex].sh_size
1035 / sizeof(struct modversion_info);
1037 for (i = 0; i < num_versions; i++) {
1038 if (strcmp(versions[i].name, symname) != 0)
1039 continue;
1041 if (versions[i].crc == maybe_relocated(*crc, crc_owner))
1042 return 1;
1043 DEBUGP("Found checksum %lX vs module %lX\n",
1044 maybe_relocated(*crc, crc_owner), versions[i].crc);
1045 goto bad_version;
1048 printk(KERN_WARNING "%s: no symbol version for %s\n",
1049 mod->name, symname);
1050 return 0;
1052 bad_version:
1053 printk("%s: disagrees about version of symbol %s\n",
1054 mod->name, symname);
1055 return 0;
1058 static inline int check_modstruct_version(Elf_Shdr *sechdrs,
1059 unsigned int versindex,
1060 struct module *mod)
1062 const unsigned long *crc;
1064 /* Since this should be found in kernel (which can't be removed),
1065 * no locking is necessary. */
1066 if (!find_symbol(MODULE_SYMBOL_PREFIX "module_layout", NULL,
1067 &crc, true, false))
1068 BUG();
1069 return check_version(sechdrs, versindex, "module_layout", mod, crc,
1070 NULL);
1073 /* First part is kernel version, which we ignore if module has crcs. */
1074 static inline int same_magic(const char *amagic, const char *bmagic,
1075 bool has_crcs)
1077 if (has_crcs) {
1078 amagic += strcspn(amagic, " ");
1079 bmagic += strcspn(bmagic, " ");
1081 return strcmp(amagic, bmagic) == 0;
1083 #else
1084 static inline int check_version(Elf_Shdr *sechdrs,
1085 unsigned int versindex,
1086 const char *symname,
1087 struct module *mod,
1088 const unsigned long *crc,
1089 const struct module *crc_owner)
1091 return 1;
1094 static inline int check_modstruct_version(Elf_Shdr *sechdrs,
1095 unsigned int versindex,
1096 struct module *mod)
1098 return 1;
1101 static inline int same_magic(const char *amagic, const char *bmagic,
1102 bool has_crcs)
1104 return strcmp(amagic, bmagic) == 0;
1106 #endif /* CONFIG_MODVERSIONS */
1108 /* Resolve a symbol for this module. I.e. if we find one, record usage. */
1109 static const struct kernel_symbol *resolve_symbol(struct module *mod,
1110 const struct load_info *info,
1111 const char *name,
1112 char ownername[])
1114 struct module *owner;
1115 const struct kernel_symbol *sym;
1116 const unsigned long *crc;
1117 int err;
1119 mutex_lock(&module_mutex);
1120 sym = find_symbol(name, &owner, &crc,
1121 !(mod->taints & (1 << TAINT_PROPRIETARY_MODULE)), true);
1122 if (!sym)
1123 goto unlock;
1125 if (!check_version(info->sechdrs, info->index.vers, name, mod, crc,
1126 owner)) {
1127 sym = ERR_PTR(-EINVAL);
1128 goto getname;
1131 err = ref_module(mod, owner);
1132 if (err) {
1133 sym = ERR_PTR(err);
1134 goto getname;
1137 getname:
1138 /* We must make copy under the lock if we failed to get ref. */
1139 strncpy(ownername, module_name(owner), MODULE_NAME_LEN);
1140 unlock:
1141 mutex_unlock(&module_mutex);
1142 return sym;
1145 static const struct kernel_symbol *
1146 resolve_symbol_wait(struct module *mod,
1147 const struct load_info *info,
1148 const char *name)
1150 const struct kernel_symbol *ksym;
1151 char owner[MODULE_NAME_LEN];
1153 if (wait_event_interruptible_timeout(module_wq,
1154 !IS_ERR(ksym = resolve_symbol(mod, info, name, owner))
1155 || PTR_ERR(ksym) != -EBUSY,
1156 30 * HZ) <= 0) {
1157 printk(KERN_WARNING "%s: gave up waiting for init of module %s.\n",
1158 mod->name, owner);
1160 return ksym;
1164 * /sys/module/foo/sections stuff
1165 * J. Corbet <corbet@lwn.net>
1167 #ifdef CONFIG_SYSFS
1169 #ifdef CONFIG_KALLSYMS
1170 static inline bool sect_empty(const Elf_Shdr *sect)
1172 return !(sect->sh_flags & SHF_ALLOC) || sect->sh_size == 0;
1175 struct module_sect_attr
1177 struct module_attribute mattr;
1178 char *name;
1179 unsigned long address;
1182 struct module_sect_attrs
1184 struct attribute_group grp;
1185 unsigned int nsections;
1186 struct module_sect_attr attrs[0];
1189 static ssize_t module_sect_show(struct module_attribute *mattr,
1190 struct module *mod, char *buf)
1192 struct module_sect_attr *sattr =
1193 container_of(mattr, struct module_sect_attr, mattr);
1194 return sprintf(buf, "0x%pK\n", (void *)sattr->address);
1197 static void free_sect_attrs(struct module_sect_attrs *sect_attrs)
1199 unsigned int section;
1201 for (section = 0; section < sect_attrs->nsections; section++)
1202 kfree(sect_attrs->attrs[section].name);
1203 kfree(sect_attrs);
1206 static void add_sect_attrs(struct module *mod, const struct load_info *info)
1208 unsigned int nloaded = 0, i, size[2];
1209 struct module_sect_attrs *sect_attrs;
1210 struct module_sect_attr *sattr;
1211 struct attribute **gattr;
1213 /* Count loaded sections and allocate structures */
1214 for (i = 0; i < info->hdr->e_shnum; i++)
1215 if (!sect_empty(&info->sechdrs[i]))
1216 nloaded++;
1217 size[0] = ALIGN(sizeof(*sect_attrs)
1218 + nloaded * sizeof(sect_attrs->attrs[0]),
1219 sizeof(sect_attrs->grp.attrs[0]));
1220 size[1] = (nloaded + 1) * sizeof(sect_attrs->grp.attrs[0]);
1221 sect_attrs = kzalloc(size[0] + size[1], GFP_KERNEL);
1222 if (sect_attrs == NULL)
1223 return;
1225 /* Setup section attributes. */
1226 sect_attrs->grp.name = "sections";
1227 sect_attrs->grp.attrs = (void *)sect_attrs + size[0];
1229 sect_attrs->nsections = 0;
1230 sattr = &sect_attrs->attrs[0];
1231 gattr = &sect_attrs->grp.attrs[0];
1232 for (i = 0; i < info->hdr->e_shnum; i++) {
1233 Elf_Shdr *sec = &info->sechdrs[i];
1234 if (sect_empty(sec))
1235 continue;
1236 sattr->address = sec->sh_addr;
1237 sattr->name = kstrdup(info->secstrings + sec->sh_name,
1238 GFP_KERNEL);
1239 if (sattr->name == NULL)
1240 goto out;
1241 sect_attrs->nsections++;
1242 sysfs_attr_init(&sattr->mattr.attr);
1243 sattr->mattr.show = module_sect_show;
1244 sattr->mattr.store = NULL;
1245 sattr->mattr.attr.name = sattr->name;
1246 sattr->mattr.attr.mode = S_IRUGO;
1247 *(gattr++) = &(sattr++)->mattr.attr;
1249 *gattr = NULL;
1251 if (sysfs_create_group(&mod->mkobj.kobj, &sect_attrs->grp))
1252 goto out;
1254 mod->sect_attrs = sect_attrs;
1255 return;
1256 out:
1257 free_sect_attrs(sect_attrs);
1260 static void remove_sect_attrs(struct module *mod)
1262 if (mod->sect_attrs) {
1263 sysfs_remove_group(&mod->mkobj.kobj,
1264 &mod->sect_attrs->grp);
1265 /* We are positive that no one is using any sect attrs
1266 * at this point. Deallocate immediately. */
1267 free_sect_attrs(mod->sect_attrs);
1268 mod->sect_attrs = NULL;
1273 * /sys/module/foo/notes/.section.name gives contents of SHT_NOTE sections.
1276 struct module_notes_attrs {
1277 struct kobject *dir;
1278 unsigned int notes;
1279 struct bin_attribute attrs[0];
1282 static ssize_t module_notes_read(struct file *filp, struct kobject *kobj,
1283 struct bin_attribute *bin_attr,
1284 char *buf, loff_t pos, size_t count)
1287 * The caller checked the pos and count against our size.
1289 memcpy(buf, bin_attr->private + pos, count);
1290 return count;
1293 static void free_notes_attrs(struct module_notes_attrs *notes_attrs,
1294 unsigned int i)
1296 if (notes_attrs->dir) {
1297 while (i-- > 0)
1298 sysfs_remove_bin_file(notes_attrs->dir,
1299 &notes_attrs->attrs[i]);
1300 kobject_put(notes_attrs->dir);
1302 kfree(notes_attrs);
1305 static void add_notes_attrs(struct module *mod, const struct load_info *info)
1307 unsigned int notes, loaded, i;
1308 struct module_notes_attrs *notes_attrs;
1309 struct bin_attribute *nattr;
1311 /* failed to create section attributes, so can't create notes */
1312 if (!mod->sect_attrs)
1313 return;
1315 /* Count notes sections and allocate structures. */
1316 notes = 0;
1317 for (i = 0; i < info->hdr->e_shnum; i++)
1318 if (!sect_empty(&info->sechdrs[i]) &&
1319 (info->sechdrs[i].sh_type == SHT_NOTE))
1320 ++notes;
1322 if (notes == 0)
1323 return;
1325 notes_attrs = kzalloc(sizeof(*notes_attrs)
1326 + notes * sizeof(notes_attrs->attrs[0]),
1327 GFP_KERNEL);
1328 if (notes_attrs == NULL)
1329 return;
1331 notes_attrs->notes = notes;
1332 nattr = &notes_attrs->attrs[0];
1333 for (loaded = i = 0; i < info->hdr->e_shnum; ++i) {
1334 if (sect_empty(&info->sechdrs[i]))
1335 continue;
1336 if (info->sechdrs[i].sh_type == SHT_NOTE) {
1337 sysfs_bin_attr_init(nattr);
1338 nattr->attr.name = mod->sect_attrs->attrs[loaded].name;
1339 nattr->attr.mode = S_IRUGO;
1340 nattr->size = info->sechdrs[i].sh_size;
1341 nattr->private = (void *) info->sechdrs[i].sh_addr;
1342 nattr->read = module_notes_read;
1343 ++nattr;
1345 ++loaded;
1348 notes_attrs->dir = kobject_create_and_add("notes", &mod->mkobj.kobj);
1349 if (!notes_attrs->dir)
1350 goto out;
1352 for (i = 0; i < notes; ++i)
1353 if (sysfs_create_bin_file(notes_attrs->dir,
1354 &notes_attrs->attrs[i]))
1355 goto out;
1357 mod->notes_attrs = notes_attrs;
1358 return;
1360 out:
1361 free_notes_attrs(notes_attrs, i);
1364 static void remove_notes_attrs(struct module *mod)
1366 if (mod->notes_attrs)
1367 free_notes_attrs(mod->notes_attrs, mod->notes_attrs->notes);
1370 #else
1372 static inline void add_sect_attrs(struct module *mod,
1373 const struct load_info *info)
1377 static inline void remove_sect_attrs(struct module *mod)
1381 static inline void add_notes_attrs(struct module *mod,
1382 const struct load_info *info)
1386 static inline void remove_notes_attrs(struct module *mod)
1389 #endif /* CONFIG_KALLSYMS */
1391 static void add_usage_links(struct module *mod)
1393 #ifdef CONFIG_MODULE_UNLOAD
1394 struct module_use *use;
1395 int nowarn;
1397 mutex_lock(&module_mutex);
1398 list_for_each_entry(use, &mod->target_list, target_list) {
1399 nowarn = sysfs_create_link(use->target->holders_dir,
1400 &mod->mkobj.kobj, mod->name);
1402 mutex_unlock(&module_mutex);
1403 #endif
1406 static void del_usage_links(struct module *mod)
1408 #ifdef CONFIG_MODULE_UNLOAD
1409 struct module_use *use;
1411 mutex_lock(&module_mutex);
1412 list_for_each_entry(use, &mod->target_list, target_list)
1413 sysfs_remove_link(use->target->holders_dir, mod->name);
1414 mutex_unlock(&module_mutex);
1415 #endif
1418 static int module_add_modinfo_attrs(struct module *mod)
1420 struct module_attribute *attr;
1421 struct module_attribute *temp_attr;
1422 int error = 0;
1423 int i;
1425 mod->modinfo_attrs = kzalloc((sizeof(struct module_attribute) *
1426 (ARRAY_SIZE(modinfo_attrs) + 1)),
1427 GFP_KERNEL);
1428 if (!mod->modinfo_attrs)
1429 return -ENOMEM;
1431 temp_attr = mod->modinfo_attrs;
1432 for (i = 0; (attr = modinfo_attrs[i]) && !error; i++) {
1433 if (!attr->test ||
1434 (attr->test && attr->test(mod))) {
1435 memcpy(temp_attr, attr, sizeof(*temp_attr));
1436 sysfs_attr_init(&temp_attr->attr);
1437 error = sysfs_create_file(&mod->mkobj.kobj,&temp_attr->attr);
1438 ++temp_attr;
1441 return error;
1444 static void module_remove_modinfo_attrs(struct module *mod)
1446 struct module_attribute *attr;
1447 int i;
1449 for (i = 0; (attr = &mod->modinfo_attrs[i]); i++) {
1450 /* pick a field to test for end of list */
1451 if (!attr->attr.name)
1452 break;
1453 sysfs_remove_file(&mod->mkobj.kobj,&attr->attr);
1454 if (attr->free)
1455 attr->free(mod);
1457 kfree(mod->modinfo_attrs);
1460 static int mod_sysfs_init(struct module *mod)
1462 int err;
1463 struct kobject *kobj;
1465 if (!module_sysfs_initialized) {
1466 printk(KERN_ERR "%s: module sysfs not initialized\n",
1467 mod->name);
1468 err = -EINVAL;
1469 goto out;
1472 kobj = kset_find_obj(module_kset, mod->name);
1473 if (kobj) {
1474 printk(KERN_ERR "%s: module is already loaded\n", mod->name);
1475 kobject_put(kobj);
1476 err = -EINVAL;
1477 goto out;
1480 mod->mkobj.mod = mod;
1482 memset(&mod->mkobj.kobj, 0, sizeof(mod->mkobj.kobj));
1483 mod->mkobj.kobj.kset = module_kset;
1484 err = kobject_init_and_add(&mod->mkobj.kobj, &module_ktype, NULL,
1485 "%s", mod->name);
1486 if (err)
1487 kobject_put(&mod->mkobj.kobj);
1489 /* delay uevent until full sysfs population */
1490 out:
1491 return err;
1494 static int mod_sysfs_setup(struct module *mod,
1495 const struct load_info *info,
1496 struct kernel_param *kparam,
1497 unsigned int num_params)
1499 int err;
1501 err = mod_sysfs_init(mod);
1502 if (err)
1503 goto out;
1505 mod->holders_dir = kobject_create_and_add("holders", &mod->mkobj.kobj);
1506 if (!mod->holders_dir) {
1507 err = -ENOMEM;
1508 goto out_unreg;
1511 err = module_param_sysfs_setup(mod, kparam, num_params);
1512 if (err)
1513 goto out_unreg_holders;
1515 err = module_add_modinfo_attrs(mod);
1516 if (err)
1517 goto out_unreg_param;
1519 add_usage_links(mod);
1520 add_sect_attrs(mod, info);
1521 add_notes_attrs(mod, info);
1523 kobject_uevent(&mod->mkobj.kobj, KOBJ_ADD);
1524 return 0;
1526 out_unreg_param:
1527 module_param_sysfs_remove(mod);
1528 out_unreg_holders:
1529 kobject_put(mod->holders_dir);
1530 out_unreg:
1531 kobject_put(&mod->mkobj.kobj);
1532 out:
1533 return err;
1536 static void mod_sysfs_fini(struct module *mod)
1538 remove_notes_attrs(mod);
1539 remove_sect_attrs(mod);
1540 kobject_put(&mod->mkobj.kobj);
1543 #else /* !CONFIG_SYSFS */
1545 static int mod_sysfs_setup(struct module *mod,
1546 const struct load_info *info,
1547 struct kernel_param *kparam,
1548 unsigned int num_params)
1550 return 0;
1553 static void mod_sysfs_fini(struct module *mod)
1557 static void module_remove_modinfo_attrs(struct module *mod)
1561 static void del_usage_links(struct module *mod)
1565 #endif /* CONFIG_SYSFS */
1567 static void mod_sysfs_teardown(struct module *mod)
1569 del_usage_links(mod);
1570 module_remove_modinfo_attrs(mod);
1571 module_param_sysfs_remove(mod);
1572 kobject_put(mod->mkobj.drivers_dir);
1573 kobject_put(mod->holders_dir);
1574 mod_sysfs_fini(mod);
1578 * unlink the module with the whole machine is stopped with interrupts off
1579 * - this defends against kallsyms not taking locks
1581 static int __unlink_module(void *_mod)
1583 struct module *mod = _mod;
1584 list_del(&mod->list);
1585 module_bug_cleanup(mod);
1586 return 0;
1589 #ifdef CONFIG_DEBUG_SET_MODULE_RONX
1591 * LKM RO/NX protection: protect module's text/ro-data
1592 * from modification and any data from execution.
1594 void set_page_attributes(void *start, void *end, int (*set)(unsigned long start, int num_pages))
1596 unsigned long begin_pfn = PFN_DOWN((unsigned long)start);
1597 unsigned long end_pfn = PFN_DOWN((unsigned long)end);
1599 if (end_pfn > begin_pfn)
1600 set(begin_pfn << PAGE_SHIFT, end_pfn - begin_pfn);
1603 static void set_section_ro_nx(void *base,
1604 unsigned long text_size,
1605 unsigned long ro_size,
1606 unsigned long total_size)
1608 /* begin and end PFNs of the current subsection */
1609 unsigned long begin_pfn;
1610 unsigned long end_pfn;
1613 * Set RO for module text and RO-data:
1614 * - Always protect first page.
1615 * - Do not protect last partial page.
1617 if (ro_size > 0)
1618 set_page_attributes(base, base + ro_size, set_memory_ro);
1621 * Set NX permissions for module data:
1622 * - Do not protect first partial page.
1623 * - Always protect last page.
1625 if (total_size > text_size) {
1626 begin_pfn = PFN_UP((unsigned long)base + text_size);
1627 end_pfn = PFN_UP((unsigned long)base + total_size);
1628 if (end_pfn > begin_pfn)
1629 set_memory_nx(begin_pfn << PAGE_SHIFT, end_pfn - begin_pfn);
1633 static void unset_module_core_ro_nx(struct module *mod)
1635 set_page_attributes(mod->module_core + mod->core_text_size,
1636 mod->module_core + mod->core_size,
1637 set_memory_x);
1638 set_page_attributes(mod->module_core,
1639 mod->module_core + mod->core_ro_size,
1640 set_memory_rw);
1643 static void unset_module_init_ro_nx(struct module *mod)
1645 set_page_attributes(mod->module_init + mod->init_text_size,
1646 mod->module_init + mod->init_size,
1647 set_memory_x);
1648 set_page_attributes(mod->module_init,
1649 mod->module_init + mod->init_ro_size,
1650 set_memory_rw);
1653 /* Iterate through all modules and set each module's text as RW */
1654 void set_all_modules_text_rw(void)
1656 struct module *mod;
1658 mutex_lock(&module_mutex);
1659 list_for_each_entry_rcu(mod, &modules, list) {
1660 if ((mod->module_core) && (mod->core_text_size)) {
1661 set_page_attributes(mod->module_core,
1662 mod->module_core + mod->core_text_size,
1663 set_memory_rw);
1665 if ((mod->module_init) && (mod->init_text_size)) {
1666 set_page_attributes(mod->module_init,
1667 mod->module_init + mod->init_text_size,
1668 set_memory_rw);
1671 mutex_unlock(&module_mutex);
1674 /* Iterate through all modules and set each module's text as RO */
1675 void set_all_modules_text_ro(void)
1677 struct module *mod;
1679 mutex_lock(&module_mutex);
1680 list_for_each_entry_rcu(mod, &modules, list) {
1681 if ((mod->module_core) && (mod->core_text_size)) {
1682 set_page_attributes(mod->module_core,
1683 mod->module_core + mod->core_text_size,
1684 set_memory_ro);
1686 if ((mod->module_init) && (mod->init_text_size)) {
1687 set_page_attributes(mod->module_init,
1688 mod->module_init + mod->init_text_size,
1689 set_memory_ro);
1692 mutex_unlock(&module_mutex);
1694 #else
1695 static inline void set_section_ro_nx(void *base, unsigned long text_size, unsigned long ro_size, unsigned long total_size) { }
1696 static void unset_module_core_ro_nx(struct module *mod) { }
1697 static void unset_module_init_ro_nx(struct module *mod) { }
1698 #endif
1700 /* Free a module, remove from lists, etc. */
1701 static void free_module(struct module *mod)
1703 trace_module_free(mod);
1705 /* Delete from various lists */
1706 mutex_lock(&module_mutex);
1707 stop_machine(__unlink_module, mod, NULL);
1708 mutex_unlock(&module_mutex);
1709 mod_sysfs_teardown(mod);
1711 /* Remove dynamic debug info */
1712 ddebug_remove_module(mod->name);
1714 /* Arch-specific cleanup. */
1715 module_arch_cleanup(mod);
1717 /* Module unload stuff */
1718 module_unload_free(mod);
1720 /* Free any allocated parameters. */
1721 destroy_params(mod->kp, mod->num_kp);
1723 /* This may be NULL, but that's OK */
1724 unset_module_init_ro_nx(mod);
1725 module_free(mod, mod->module_init);
1726 kfree(mod->args);
1727 percpu_modfree(mod);
1729 /* Free lock-classes: */
1730 lockdep_free_key_range(mod->module_core, mod->core_size);
1732 /* Finally, free the core (containing the module structure) */
1733 unset_module_core_ro_nx(mod);
1734 module_free(mod, mod->module_core);
1736 #ifdef CONFIG_MPU
1737 update_protections(current->mm);
1738 #endif
1741 void *__symbol_get(const char *symbol)
1743 struct module *owner;
1744 const struct kernel_symbol *sym;
1746 preempt_disable();
1747 sym = find_symbol(symbol, &owner, NULL, true, true);
1748 if (sym && strong_try_module_get(owner))
1749 sym = NULL;
1750 preempt_enable();
1752 return sym ? (void *)sym->value : NULL;
1754 EXPORT_SYMBOL_GPL(__symbol_get);
1757 * Ensure that an exported symbol [global namespace] does not already exist
1758 * in the kernel or in some other module's exported symbol table.
1760 * You must hold the module_mutex.
1762 static int verify_export_symbols(struct module *mod)
1764 unsigned int i;
1765 struct module *owner;
1766 const struct kernel_symbol *s;
1767 struct {
1768 const struct kernel_symbol *sym;
1769 unsigned int num;
1770 } arr[] = {
1771 { mod->syms, mod->num_syms },
1772 { mod->gpl_syms, mod->num_gpl_syms },
1773 { mod->gpl_future_syms, mod->num_gpl_future_syms },
1774 #ifdef CONFIG_UNUSED_SYMBOLS
1775 { mod->unused_syms, mod->num_unused_syms },
1776 { mod->unused_gpl_syms, mod->num_unused_gpl_syms },
1777 #endif
1780 for (i = 0; i < ARRAY_SIZE(arr); i++) {
1781 for (s = arr[i].sym; s < arr[i].sym + arr[i].num; s++) {
1782 if (find_symbol(s->name, &owner, NULL, true, false)) {
1783 printk(KERN_ERR
1784 "%s: exports duplicate symbol %s"
1785 " (owned by %s)\n",
1786 mod->name, s->name, module_name(owner));
1787 return -ENOEXEC;
1791 return 0;
1794 /* Change all symbols so that st_value encodes the pointer directly. */
1795 static int simplify_symbols(struct module *mod, const struct load_info *info)
1797 Elf_Shdr *symsec = &info->sechdrs[info->index.sym];
1798 Elf_Sym *sym = (void *)symsec->sh_addr;
1799 unsigned long secbase;
1800 unsigned int i;
1801 int ret = 0;
1802 const struct kernel_symbol *ksym;
1804 for (i = 1; i < symsec->sh_size / sizeof(Elf_Sym); i++) {
1805 const char *name = info->strtab + sym[i].st_name;
1807 switch (sym[i].st_shndx) {
1808 case SHN_COMMON:
1809 /* We compiled with -fno-common. These are not
1810 supposed to happen. */
1811 DEBUGP("Common symbol: %s\n", name);
1812 printk("%s: please compile with -fno-common\n",
1813 mod->name);
1814 ret = -ENOEXEC;
1815 break;
1817 case SHN_ABS:
1818 /* Don't need to do anything */
1819 DEBUGP("Absolute symbol: 0x%08lx\n",
1820 (long)sym[i].st_value);
1821 break;
1823 case SHN_UNDEF:
1824 ksym = resolve_symbol_wait(mod, info, name);
1825 /* Ok if resolved. */
1826 if (ksym && !IS_ERR(ksym)) {
1827 sym[i].st_value = ksym->value;
1828 break;
1831 /* Ok if weak. */
1832 if (!ksym && ELF_ST_BIND(sym[i].st_info) == STB_WEAK)
1833 break;
1835 printk(KERN_WARNING "%s: Unknown symbol %s (err %li)\n",
1836 mod->name, name, PTR_ERR(ksym));
1837 ret = PTR_ERR(ksym) ?: -ENOENT;
1838 break;
1840 default:
1841 /* Divert to percpu allocation if a percpu var. */
1842 if (sym[i].st_shndx == info->index.pcpu)
1843 secbase = (unsigned long)mod_percpu(mod);
1844 else
1845 secbase = info->sechdrs[sym[i].st_shndx].sh_addr;
1846 sym[i].st_value += secbase;
1847 break;
1851 return ret;
1854 static int apply_relocations(struct module *mod, const struct load_info *info)
1856 unsigned int i;
1857 int err = 0;
1859 /* Now do relocations. */
1860 for (i = 1; i < info->hdr->e_shnum; i++) {
1861 unsigned int infosec = info->sechdrs[i].sh_info;
1863 /* Not a valid relocation section? */
1864 if (infosec >= info->hdr->e_shnum)
1865 continue;
1867 /* Don't bother with non-allocated sections */
1868 if (!(info->sechdrs[infosec].sh_flags & SHF_ALLOC))
1869 continue;
1871 if (info->sechdrs[i].sh_type == SHT_REL)
1872 err = apply_relocate(info->sechdrs, info->strtab,
1873 info->index.sym, i, mod);
1874 else if (info->sechdrs[i].sh_type == SHT_RELA)
1875 err = apply_relocate_add(info->sechdrs, info->strtab,
1876 info->index.sym, i, mod);
1877 if (err < 0)
1878 break;
1880 return err;
1883 /* Additional bytes needed by arch in front of individual sections */
1884 unsigned int __weak arch_mod_section_prepend(struct module *mod,
1885 unsigned int section)
1887 /* default implementation just returns zero */
1888 return 0;
1891 /* Update size with this section: return offset. */
1892 static long get_offset(struct module *mod, unsigned int *size,
1893 Elf_Shdr *sechdr, unsigned int section)
1895 long ret;
1897 *size += arch_mod_section_prepend(mod, section);
1898 ret = ALIGN(*size, sechdr->sh_addralign ?: 1);
1899 *size = ret + sechdr->sh_size;
1900 return ret;
1903 /* Lay out the SHF_ALLOC sections in a way not dissimilar to how ld
1904 might -- code, read-only data, read-write data, small data. Tally
1905 sizes, and place the offsets into sh_entsize fields: high bit means it
1906 belongs in init. */
1907 static void layout_sections(struct module *mod, struct load_info *info)
1909 static unsigned long const masks[][2] = {
1910 /* NOTE: all executable code must be the first section
1911 * in this array; otherwise modify the text_size
1912 * finder in the two loops below */
1913 { SHF_EXECINSTR | SHF_ALLOC, ARCH_SHF_SMALL },
1914 { SHF_ALLOC, SHF_WRITE | ARCH_SHF_SMALL },
1915 { SHF_WRITE | SHF_ALLOC, ARCH_SHF_SMALL },
1916 { ARCH_SHF_SMALL | SHF_ALLOC, 0 }
1918 unsigned int m, i;
1920 for (i = 0; i < info->hdr->e_shnum; i++)
1921 info->sechdrs[i].sh_entsize = ~0UL;
1923 DEBUGP("Core section allocation order:\n");
1924 for (m = 0; m < ARRAY_SIZE(masks); ++m) {
1925 for (i = 0; i < info->hdr->e_shnum; ++i) {
1926 Elf_Shdr *s = &info->sechdrs[i];
1927 const char *sname = info->secstrings + s->sh_name;
1929 if ((s->sh_flags & masks[m][0]) != masks[m][0]
1930 || (s->sh_flags & masks[m][1])
1931 || s->sh_entsize != ~0UL
1932 || strstarts(sname, ".init"))
1933 continue;
1934 s->sh_entsize = get_offset(mod, &mod->core_size, s, i);
1935 DEBUGP("\t%s\n", name);
1937 switch (m) {
1938 case 0: /* executable */
1939 mod->core_size = debug_align(mod->core_size);
1940 mod->core_text_size = mod->core_size;
1941 break;
1942 case 1: /* RO: text and ro-data */
1943 mod->core_size = debug_align(mod->core_size);
1944 mod->core_ro_size = mod->core_size;
1945 break;
1946 case 3: /* whole core */
1947 mod->core_size = debug_align(mod->core_size);
1948 break;
1952 DEBUGP("Init section allocation order:\n");
1953 for (m = 0; m < ARRAY_SIZE(masks); ++m) {
1954 for (i = 0; i < info->hdr->e_shnum; ++i) {
1955 Elf_Shdr *s = &info->sechdrs[i];
1956 const char *sname = info->secstrings + s->sh_name;
1958 if ((s->sh_flags & masks[m][0]) != masks[m][0]
1959 || (s->sh_flags & masks[m][1])
1960 || s->sh_entsize != ~0UL
1961 || !strstarts(sname, ".init"))
1962 continue;
1963 s->sh_entsize = (get_offset(mod, &mod->init_size, s, i)
1964 | INIT_OFFSET_MASK);
1965 DEBUGP("\t%s\n", sname);
1967 switch (m) {
1968 case 0: /* executable */
1969 mod->init_size = debug_align(mod->init_size);
1970 mod->init_text_size = mod->init_size;
1971 break;
1972 case 1: /* RO: text and ro-data */
1973 mod->init_size = debug_align(mod->init_size);
1974 mod->init_ro_size = mod->init_size;
1975 break;
1976 case 3: /* whole init */
1977 mod->init_size = debug_align(mod->init_size);
1978 break;
1983 static void set_license(struct module *mod, const char *license)
1985 if (!license)
1986 license = "unspecified";
1988 if (!license_is_gpl_compatible(license)) {
1989 if (!test_taint(TAINT_PROPRIETARY_MODULE))
1990 printk(KERN_WARNING "%s: module license '%s' taints "
1991 "kernel.\n", mod->name, license);
1992 add_taint_module(mod, TAINT_PROPRIETARY_MODULE);
1996 /* Parse tag=value strings from .modinfo section */
1997 static char *next_string(char *string, unsigned long *secsize)
1999 /* Skip non-zero chars */
2000 while (string[0]) {
2001 string++;
2002 if ((*secsize)-- <= 1)
2003 return NULL;
2006 /* Skip any zero padding. */
2007 while (!string[0]) {
2008 string++;
2009 if ((*secsize)-- <= 1)
2010 return NULL;
2012 return string;
2015 static char *get_modinfo(struct load_info *info, const char *tag)
2017 char *p;
2018 unsigned int taglen = strlen(tag);
2019 Elf_Shdr *infosec = &info->sechdrs[info->index.info];
2020 unsigned long size = infosec->sh_size;
2022 for (p = (char *)infosec->sh_addr; p; p = next_string(p, &size)) {
2023 if (strncmp(p, tag, taglen) == 0 && p[taglen] == '=')
2024 return p + taglen + 1;
2026 return NULL;
2029 static void setup_modinfo(struct module *mod, struct load_info *info)
2031 struct module_attribute *attr;
2032 int i;
2034 for (i = 0; (attr = modinfo_attrs[i]); i++) {
2035 if (attr->setup)
2036 attr->setup(mod, get_modinfo(info, attr->attr.name));
2040 static void free_modinfo(struct module *mod)
2042 struct module_attribute *attr;
2043 int i;
2045 for (i = 0; (attr = modinfo_attrs[i]); i++) {
2046 if (attr->free)
2047 attr->free(mod);
2051 #ifdef CONFIG_KALLSYMS
2053 /* lookup symbol in given range of kernel_symbols */
2054 static const struct kernel_symbol *lookup_symbol(const char *name,
2055 const struct kernel_symbol *start,
2056 const struct kernel_symbol *stop)
2058 return bsearch(name, start, stop - start,
2059 sizeof(struct kernel_symbol), cmp_name);
2062 static int is_exported(const char *name, unsigned long value,
2063 const struct module *mod)
2065 const struct kernel_symbol *ks;
2066 if (!mod)
2067 ks = lookup_symbol(name, __start___ksymtab, __stop___ksymtab);
2068 else
2069 ks = lookup_symbol(name, mod->syms, mod->syms + mod->num_syms);
2070 return ks != NULL && ks->value == value;
2073 /* As per nm */
2074 static char elf_type(const Elf_Sym *sym, const struct load_info *info)
2076 const Elf_Shdr *sechdrs = info->sechdrs;
2078 if (ELF_ST_BIND(sym->st_info) == STB_WEAK) {
2079 if (ELF_ST_TYPE(sym->st_info) == STT_OBJECT)
2080 return 'v';
2081 else
2082 return 'w';
2084 if (sym->st_shndx == SHN_UNDEF)
2085 return 'U';
2086 if (sym->st_shndx == SHN_ABS)
2087 return 'a';
2088 if (sym->st_shndx >= SHN_LORESERVE)
2089 return '?';
2090 if (sechdrs[sym->st_shndx].sh_flags & SHF_EXECINSTR)
2091 return 't';
2092 if (sechdrs[sym->st_shndx].sh_flags & SHF_ALLOC
2093 && sechdrs[sym->st_shndx].sh_type != SHT_NOBITS) {
2094 if (!(sechdrs[sym->st_shndx].sh_flags & SHF_WRITE))
2095 return 'r';
2096 else if (sechdrs[sym->st_shndx].sh_flags & ARCH_SHF_SMALL)
2097 return 'g';
2098 else
2099 return 'd';
2101 if (sechdrs[sym->st_shndx].sh_type == SHT_NOBITS) {
2102 if (sechdrs[sym->st_shndx].sh_flags & ARCH_SHF_SMALL)
2103 return 's';
2104 else
2105 return 'b';
2107 if (strstarts(info->secstrings + sechdrs[sym->st_shndx].sh_name,
2108 ".debug")) {
2109 return 'n';
2111 return '?';
2114 static bool is_core_symbol(const Elf_Sym *src, const Elf_Shdr *sechdrs,
2115 unsigned int shnum)
2117 const Elf_Shdr *sec;
2119 if (src->st_shndx == SHN_UNDEF
2120 || src->st_shndx >= shnum
2121 || !src->st_name)
2122 return false;
2124 sec = sechdrs + src->st_shndx;
2125 if (!(sec->sh_flags & SHF_ALLOC)
2126 #ifndef CONFIG_KALLSYMS_ALL
2127 || !(sec->sh_flags & SHF_EXECINSTR)
2128 #endif
2129 || (sec->sh_entsize & INIT_OFFSET_MASK))
2130 return false;
2132 return true;
2135 static void layout_symtab(struct module *mod, struct load_info *info)
2137 Elf_Shdr *symsect = info->sechdrs + info->index.sym;
2138 Elf_Shdr *strsect = info->sechdrs + info->index.str;
2139 const Elf_Sym *src;
2140 unsigned int i, nsrc, ndst;
2142 /* Put symbol section at end of init part of module. */
2143 symsect->sh_flags |= SHF_ALLOC;
2144 symsect->sh_entsize = get_offset(mod, &mod->init_size, symsect,
2145 info->index.sym) | INIT_OFFSET_MASK;
2146 DEBUGP("\t%s\n", info->secstrings + symsect->sh_name);
2148 src = (void *)info->hdr + symsect->sh_offset;
2149 nsrc = symsect->sh_size / sizeof(*src);
2150 for (ndst = i = 1; i < nsrc; ++i, ++src)
2151 if (is_core_symbol(src, info->sechdrs, info->hdr->e_shnum)) {
2152 unsigned int j = src->st_name;
2154 while (!__test_and_set_bit(j, info->strmap)
2155 && info->strtab[j])
2156 ++j;
2157 ++ndst;
2160 /* Append room for core symbols at end of core part. */
2161 info->symoffs = ALIGN(mod->core_size, symsect->sh_addralign ?: 1);
2162 mod->core_size = info->symoffs + ndst * sizeof(Elf_Sym);
2164 /* Put string table section at end of init part of module. */
2165 strsect->sh_flags |= SHF_ALLOC;
2166 strsect->sh_entsize = get_offset(mod, &mod->init_size, strsect,
2167 info->index.str) | INIT_OFFSET_MASK;
2168 DEBUGP("\t%s\n", info->secstrings + strsect->sh_name);
2170 /* Append room for core symbols' strings at end of core part. */
2171 info->stroffs = mod->core_size;
2172 __set_bit(0, info->strmap);
2173 mod->core_size += bitmap_weight(info->strmap, strsect->sh_size);
2176 static void add_kallsyms(struct module *mod, const struct load_info *info)
2178 unsigned int i, ndst;
2179 const Elf_Sym *src;
2180 Elf_Sym *dst;
2181 char *s;
2182 Elf_Shdr *symsec = &info->sechdrs[info->index.sym];
2184 mod->symtab = (void *)symsec->sh_addr;
2185 mod->num_symtab = symsec->sh_size / sizeof(Elf_Sym);
2186 /* Make sure we get permanent strtab: don't use info->strtab. */
2187 mod->strtab = (void *)info->sechdrs[info->index.str].sh_addr;
2189 /* Set types up while we still have access to sections. */
2190 for (i = 0; i < mod->num_symtab; i++)
2191 mod->symtab[i].st_info = elf_type(&mod->symtab[i], info);
2193 mod->core_symtab = dst = mod->module_core + info->symoffs;
2194 src = mod->symtab;
2195 *dst = *src;
2196 for (ndst = i = 1; i < mod->num_symtab; ++i, ++src) {
2197 if (!is_core_symbol(src, info->sechdrs, info->hdr->e_shnum))
2198 continue;
2199 dst[ndst] = *src;
2200 dst[ndst].st_name = bitmap_weight(info->strmap,
2201 dst[ndst].st_name);
2202 ++ndst;
2204 mod->core_num_syms = ndst;
2206 mod->core_strtab = s = mod->module_core + info->stroffs;
2207 for (*s = 0, i = 1; i < info->sechdrs[info->index.str].sh_size; ++i)
2208 if (test_bit(i, info->strmap))
2209 *++s = mod->strtab[i];
2211 #else
2212 static inline void layout_symtab(struct module *mod, struct load_info *info)
2216 static void add_kallsyms(struct module *mod, const struct load_info *info)
2219 #endif /* CONFIG_KALLSYMS */
2221 static void dynamic_debug_setup(struct _ddebug *debug, unsigned int num)
2223 if (!debug)
2224 return;
2225 #ifdef CONFIG_DYNAMIC_DEBUG
2226 if (ddebug_add_module(debug, num, debug->modname))
2227 printk(KERN_ERR "dynamic debug error adding module: %s\n",
2228 debug->modname);
2229 #endif
2232 static void dynamic_debug_remove(struct _ddebug *debug)
2234 if (debug)
2235 ddebug_remove_module(debug->modname);
2238 static void *module_alloc_update_bounds(unsigned long size)
2240 void *ret = module_alloc(size);
2242 if (ret) {
2243 mutex_lock(&module_mutex);
2244 /* Update module bounds. */
2245 if ((unsigned long)ret < module_addr_min)
2246 module_addr_min = (unsigned long)ret;
2247 if ((unsigned long)ret + size > module_addr_max)
2248 module_addr_max = (unsigned long)ret + size;
2249 mutex_unlock(&module_mutex);
2251 return ret;
2254 #ifdef CONFIG_DEBUG_KMEMLEAK
2255 static void kmemleak_load_module(const struct module *mod,
2256 const struct load_info *info)
2258 unsigned int i;
2260 /* only scan the sections containing data */
2261 kmemleak_scan_area(mod, sizeof(struct module), GFP_KERNEL);
2263 for (i = 1; i < info->hdr->e_shnum; i++) {
2264 const char *name = info->secstrings + info->sechdrs[i].sh_name;
2265 if (!(info->sechdrs[i].sh_flags & SHF_ALLOC))
2266 continue;
2267 if (!strstarts(name, ".data") && !strstarts(name, ".bss"))
2268 continue;
2270 kmemleak_scan_area((void *)info->sechdrs[i].sh_addr,
2271 info->sechdrs[i].sh_size, GFP_KERNEL);
2274 #else
2275 static inline void kmemleak_load_module(const struct module *mod,
2276 const struct load_info *info)
2279 #endif
2281 /* Sets info->hdr and info->len. */
2282 static int copy_and_check(struct load_info *info,
2283 const void __user *umod, unsigned long len,
2284 const char __user *uargs)
2286 int err;
2287 Elf_Ehdr *hdr;
2289 if (len < sizeof(*hdr))
2290 return -ENOEXEC;
2292 /* Suck in entire file: we'll want most of it. */
2293 if ((hdr = vmalloc(len)) == NULL)
2294 return -ENOMEM;
2296 if (copy_from_user(hdr, umod, len) != 0) {
2297 err = -EFAULT;
2298 goto free_hdr;
2301 /* Sanity checks against insmoding binaries or wrong arch,
2302 weird elf version */
2303 if (memcmp(hdr->e_ident, ELFMAG, SELFMAG) != 0
2304 || hdr->e_type != ET_REL
2305 || !elf_check_arch(hdr)
2306 || hdr->e_shentsize != sizeof(Elf_Shdr)) {
2307 err = -ENOEXEC;
2308 goto free_hdr;
2311 if (len < hdr->e_shoff + hdr->e_shnum * sizeof(Elf_Shdr)) {
2312 err = -ENOEXEC;
2313 goto free_hdr;
2316 info->hdr = hdr;
2317 info->len = len;
2318 return 0;
2320 free_hdr:
2321 vfree(hdr);
2322 return err;
2325 static void free_copy(struct load_info *info)
2327 vfree(info->hdr);
2330 static int rewrite_section_headers(struct load_info *info)
2332 unsigned int i;
2334 /* This should always be true, but let's be sure. */
2335 info->sechdrs[0].sh_addr = 0;
2337 for (i = 1; i < info->hdr->e_shnum; i++) {
2338 Elf_Shdr *shdr = &info->sechdrs[i];
2339 if (shdr->sh_type != SHT_NOBITS
2340 && info->len < shdr->sh_offset + shdr->sh_size) {
2341 printk(KERN_ERR "Module len %lu truncated\n",
2342 info->len);
2343 return -ENOEXEC;
2346 /* Mark all sections sh_addr with their address in the
2347 temporary image. */
2348 shdr->sh_addr = (size_t)info->hdr + shdr->sh_offset;
2350 #ifndef CONFIG_MODULE_UNLOAD
2351 /* Don't load .exit sections */
2352 if (strstarts(info->secstrings+shdr->sh_name, ".exit"))
2353 shdr->sh_flags &= ~(unsigned long)SHF_ALLOC;
2354 #endif
2357 /* Track but don't keep modinfo and version sections. */
2358 info->index.vers = find_sec(info, "__versions");
2359 info->index.info = find_sec(info, ".modinfo");
2360 info->sechdrs[info->index.info].sh_flags &= ~(unsigned long)SHF_ALLOC;
2361 info->sechdrs[info->index.vers].sh_flags &= ~(unsigned long)SHF_ALLOC;
2362 return 0;
2366 * Set up our basic convenience variables (pointers to section headers,
2367 * search for module section index etc), and do some basic section
2368 * verification.
2370 * Return the temporary module pointer (we'll replace it with the final
2371 * one when we move the module sections around).
2373 static struct module *setup_load_info(struct load_info *info)
2375 unsigned int i;
2376 int err;
2377 struct module *mod;
2379 /* Set up the convenience variables */
2380 info->sechdrs = (void *)info->hdr + info->hdr->e_shoff;
2381 info->secstrings = (void *)info->hdr
2382 + info->sechdrs[info->hdr->e_shstrndx].sh_offset;
2384 err = rewrite_section_headers(info);
2385 if (err)
2386 return ERR_PTR(err);
2388 /* Find internal symbols and strings. */
2389 for (i = 1; i < info->hdr->e_shnum; i++) {
2390 if (info->sechdrs[i].sh_type == SHT_SYMTAB) {
2391 info->index.sym = i;
2392 info->index.str = info->sechdrs[i].sh_link;
2393 info->strtab = (char *)info->hdr
2394 + info->sechdrs[info->index.str].sh_offset;
2395 break;
2399 info->index.mod = find_sec(info, ".gnu.linkonce.this_module");
2400 if (!info->index.mod) {
2401 printk(KERN_WARNING "No module found in object\n");
2402 return ERR_PTR(-ENOEXEC);
2404 /* This is temporary: point mod into copy of data. */
2405 mod = (void *)info->sechdrs[info->index.mod].sh_addr;
2407 if (info->index.sym == 0) {
2408 printk(KERN_WARNING "%s: module has no symbols (stripped?)\n",
2409 mod->name);
2410 return ERR_PTR(-ENOEXEC);
2413 info->index.pcpu = find_pcpusec(info);
2415 /* Check module struct version now, before we try to use module. */
2416 if (!check_modstruct_version(info->sechdrs, info->index.vers, mod))
2417 return ERR_PTR(-ENOEXEC);
2419 return mod;
2422 static int check_modinfo(struct module *mod, struct load_info *info)
2424 const char *modmagic = get_modinfo(info, "vermagic");
2425 int err;
2427 /* This is allowed: modprobe --force will invalidate it. */
2428 if (!modmagic) {
2429 err = try_to_force_load(mod, "bad vermagic");
2430 if (err)
2431 return err;
2432 } else if (!same_magic(modmagic, vermagic, info->index.vers)) {
2433 printk(KERN_ERR "%s: version magic '%s' should be '%s'\n",
2434 mod->name, modmagic, vermagic);
2435 return -ENOEXEC;
2438 if (get_modinfo(info, "staging")) {
2439 add_taint_module(mod, TAINT_CRAP);
2440 printk(KERN_WARNING "%s: module is from the staging directory,"
2441 " the quality is unknown, you have been warned.\n",
2442 mod->name);
2445 /* Set up license info based on the info section */
2446 set_license(mod, get_modinfo(info, "license"));
2448 return 0;
2451 static void find_module_sections(struct module *mod, struct load_info *info)
2453 mod->kp = section_objs(info, "__param",
2454 sizeof(*mod->kp), &mod->num_kp);
2455 mod->syms = section_objs(info, "__ksymtab",
2456 sizeof(*mod->syms), &mod->num_syms);
2457 mod->crcs = section_addr(info, "__kcrctab");
2458 mod->gpl_syms = section_objs(info, "__ksymtab_gpl",
2459 sizeof(*mod->gpl_syms),
2460 &mod->num_gpl_syms);
2461 mod->gpl_crcs = section_addr(info, "__kcrctab_gpl");
2462 mod->gpl_future_syms = section_objs(info,
2463 "__ksymtab_gpl_future",
2464 sizeof(*mod->gpl_future_syms),
2465 &mod->num_gpl_future_syms);
2466 mod->gpl_future_crcs = section_addr(info, "__kcrctab_gpl_future");
2468 #ifdef CONFIG_UNUSED_SYMBOLS
2469 mod->unused_syms = section_objs(info, "__ksymtab_unused",
2470 sizeof(*mod->unused_syms),
2471 &mod->num_unused_syms);
2472 mod->unused_crcs = section_addr(info, "__kcrctab_unused");
2473 mod->unused_gpl_syms = section_objs(info, "__ksymtab_unused_gpl",
2474 sizeof(*mod->unused_gpl_syms),
2475 &mod->num_unused_gpl_syms);
2476 mod->unused_gpl_crcs = section_addr(info, "__kcrctab_unused_gpl");
2477 #endif
2478 #ifdef CONFIG_CONSTRUCTORS
2479 mod->ctors = section_objs(info, ".ctors",
2480 sizeof(*mod->ctors), &mod->num_ctors);
2481 #endif
2483 #ifdef CONFIG_TRACEPOINTS
2484 mod->tracepoints_ptrs = section_objs(info, "__tracepoints_ptrs",
2485 sizeof(*mod->tracepoints_ptrs),
2486 &mod->num_tracepoints);
2487 #endif
2488 #ifdef HAVE_JUMP_LABEL
2489 mod->jump_entries = section_objs(info, "__jump_table",
2490 sizeof(*mod->jump_entries),
2491 &mod->num_jump_entries);
2492 #endif
2493 #ifdef CONFIG_EVENT_TRACING
2494 mod->trace_events = section_objs(info, "_ftrace_events",
2495 sizeof(*mod->trace_events),
2496 &mod->num_trace_events);
2498 * This section contains pointers to allocated objects in the trace
2499 * code and not scanning it leads to false positives.
2501 kmemleak_scan_area(mod->trace_events, sizeof(*mod->trace_events) *
2502 mod->num_trace_events, GFP_KERNEL);
2503 #endif
2504 #ifdef CONFIG_TRACING
2505 mod->trace_bprintk_fmt_start = section_objs(info, "__trace_printk_fmt",
2506 sizeof(*mod->trace_bprintk_fmt_start),
2507 &mod->num_trace_bprintk_fmt);
2509 * This section contains pointers to allocated objects in the trace
2510 * code and not scanning it leads to false positives.
2512 kmemleak_scan_area(mod->trace_bprintk_fmt_start,
2513 sizeof(*mod->trace_bprintk_fmt_start) *
2514 mod->num_trace_bprintk_fmt, GFP_KERNEL);
2515 #endif
2516 #ifdef CONFIG_FTRACE_MCOUNT_RECORD
2517 /* sechdrs[0].sh_size is always zero */
2518 mod->ftrace_callsites = section_objs(info, "__mcount_loc",
2519 sizeof(*mod->ftrace_callsites),
2520 &mod->num_ftrace_callsites);
2521 #endif
2523 mod->extable = section_objs(info, "__ex_table",
2524 sizeof(*mod->extable), &mod->num_exentries);
2526 if (section_addr(info, "__obsparm"))
2527 printk(KERN_WARNING "%s: Ignoring obsolete parameters\n",
2528 mod->name);
2530 info->debug = section_objs(info, "__verbose",
2531 sizeof(*info->debug), &info->num_debug);
2534 static int move_module(struct module *mod, struct load_info *info)
2536 int i;
2537 void *ptr;
2539 /* Do the allocs. */
2540 ptr = module_alloc_update_bounds(mod->core_size);
2542 * The pointer to this block is stored in the module structure
2543 * which is inside the block. Just mark it as not being a
2544 * leak.
2546 kmemleak_not_leak(ptr);
2547 if (!ptr)
2548 return -ENOMEM;
2550 memset(ptr, 0, mod->core_size);
2551 mod->module_core = ptr;
2553 ptr = module_alloc_update_bounds(mod->init_size);
2555 * The pointer to this block is stored in the module structure
2556 * which is inside the block. This block doesn't need to be
2557 * scanned as it contains data and code that will be freed
2558 * after the module is initialized.
2560 kmemleak_ignore(ptr);
2561 if (!ptr && mod->init_size) {
2562 module_free(mod, mod->module_core);
2563 return -ENOMEM;
2565 memset(ptr, 0, mod->init_size);
2566 mod->module_init = ptr;
2568 /* Transfer each section which specifies SHF_ALLOC */
2569 DEBUGP("final section addresses:\n");
2570 for (i = 0; i < info->hdr->e_shnum; i++) {
2571 void *dest;
2572 Elf_Shdr *shdr = &info->sechdrs[i];
2574 if (!(shdr->sh_flags & SHF_ALLOC))
2575 continue;
2577 if (shdr->sh_entsize & INIT_OFFSET_MASK)
2578 dest = mod->module_init
2579 + (shdr->sh_entsize & ~INIT_OFFSET_MASK);
2580 else
2581 dest = mod->module_core + shdr->sh_entsize;
2583 if (shdr->sh_type != SHT_NOBITS)
2584 memcpy(dest, (void *)shdr->sh_addr, shdr->sh_size);
2585 /* Update sh_addr to point to copy in image. */
2586 shdr->sh_addr = (unsigned long)dest;
2587 DEBUGP("\t0x%lx %s\n",
2588 shdr->sh_addr, info->secstrings + shdr->sh_name);
2591 return 0;
2594 static int check_module_license_and_versions(struct module *mod)
2597 * ndiswrapper is under GPL by itself, but loads proprietary modules.
2598 * Don't use add_taint_module(), as it would prevent ndiswrapper from
2599 * using GPL-only symbols it needs.
2601 if (strcmp(mod->name, "ndiswrapper") == 0)
2602 add_taint(TAINT_PROPRIETARY_MODULE);
2604 /* driverloader was caught wrongly pretending to be under GPL */
2605 if (strcmp(mod->name, "driverloader") == 0)
2606 add_taint_module(mod, TAINT_PROPRIETARY_MODULE);
2608 #ifdef CONFIG_MODVERSIONS
2609 if ((mod->num_syms && !mod->crcs)
2610 || (mod->num_gpl_syms && !mod->gpl_crcs)
2611 || (mod->num_gpl_future_syms && !mod->gpl_future_crcs)
2612 #ifdef CONFIG_UNUSED_SYMBOLS
2613 || (mod->num_unused_syms && !mod->unused_crcs)
2614 || (mod->num_unused_gpl_syms && !mod->unused_gpl_crcs)
2615 #endif
2617 return try_to_force_load(mod,
2618 "no versions for exported symbols");
2620 #endif
2621 return 0;
2624 static void flush_module_icache(const struct module *mod)
2626 mm_segment_t old_fs;
2628 /* flush the icache in correct context */
2629 old_fs = get_fs();
2630 set_fs(KERNEL_DS);
2633 * Flush the instruction cache, since we've played with text.
2634 * Do it before processing of module parameters, so the module
2635 * can provide parameter accessor functions of its own.
2637 if (mod->module_init)
2638 flush_icache_range((unsigned long)mod->module_init,
2639 (unsigned long)mod->module_init
2640 + mod->init_size);
2641 flush_icache_range((unsigned long)mod->module_core,
2642 (unsigned long)mod->module_core + mod->core_size);
2644 set_fs(old_fs);
2647 static struct module *layout_and_allocate(struct load_info *info)
2649 /* Module within temporary copy. */
2650 struct module *mod;
2651 Elf_Shdr *pcpusec;
2652 int err;
2654 mod = setup_load_info(info);
2655 if (IS_ERR(mod))
2656 return mod;
2658 err = check_modinfo(mod, info);
2659 if (err)
2660 return ERR_PTR(err);
2662 /* Allow arches to frob section contents and sizes. */
2663 err = module_frob_arch_sections(info->hdr, info->sechdrs,
2664 info->secstrings, mod);
2665 if (err < 0)
2666 goto out;
2668 pcpusec = &info->sechdrs[info->index.pcpu];
2669 if (pcpusec->sh_size) {
2670 /* We have a special allocation for this section. */
2671 err = percpu_modalloc(mod,
2672 pcpusec->sh_size, pcpusec->sh_addralign);
2673 if (err)
2674 goto out;
2675 pcpusec->sh_flags &= ~(unsigned long)SHF_ALLOC;
2678 /* Determine total sizes, and put offsets in sh_entsize. For now
2679 this is done generically; there doesn't appear to be any
2680 special cases for the architectures. */
2681 layout_sections(mod, info);
2683 info->strmap = kzalloc(BITS_TO_LONGS(info->sechdrs[info->index.str].sh_size)
2684 * sizeof(long), GFP_KERNEL);
2685 if (!info->strmap) {
2686 err = -ENOMEM;
2687 goto free_percpu;
2689 layout_symtab(mod, info);
2691 /* Allocate and move to the final place */
2692 err = move_module(mod, info);
2693 if (err)
2694 goto free_strmap;
2696 /* Module has been copied to its final place now: return it. */
2697 mod = (void *)info->sechdrs[info->index.mod].sh_addr;
2698 kmemleak_load_module(mod, info);
2699 return mod;
2701 free_strmap:
2702 kfree(info->strmap);
2703 free_percpu:
2704 percpu_modfree(mod);
2705 out:
2706 return ERR_PTR(err);
2709 /* mod is no longer valid after this! */
2710 static void module_deallocate(struct module *mod, struct load_info *info)
2712 kfree(info->strmap);
2713 percpu_modfree(mod);
2714 module_free(mod, mod->module_init);
2715 module_free(mod, mod->module_core);
2718 static int post_relocation(struct module *mod, const struct load_info *info)
2720 /* Sort exception table now relocations are done. */
2721 sort_extable(mod->extable, mod->extable + mod->num_exentries);
2723 /* Copy relocated percpu area over. */
2724 percpu_modcopy(mod, (void *)info->sechdrs[info->index.pcpu].sh_addr,
2725 info->sechdrs[info->index.pcpu].sh_size);
2727 /* Setup kallsyms-specific fields. */
2728 add_kallsyms(mod, info);
2730 /* Arch-specific module finalizing. */
2731 return module_finalize(info->hdr, info->sechdrs, mod);
2734 /* Allocate and load the module: note that size of section 0 is always
2735 zero, and we rely on this for optional sections. */
2736 static struct module *load_module(void __user *umod,
2737 unsigned long len,
2738 const char __user *uargs)
2740 struct load_info info = { NULL, };
2741 struct module *mod;
2742 long err;
2744 DEBUGP("load_module: umod=%p, len=%lu, uargs=%p\n",
2745 umod, len, uargs);
2747 /* Copy in the blobs from userspace, check they are vaguely sane. */
2748 err = copy_and_check(&info, umod, len, uargs);
2749 if (err)
2750 return ERR_PTR(err);
2752 /* Figure out module layout, and allocate all the memory. */
2753 mod = layout_and_allocate(&info);
2754 if (IS_ERR(mod)) {
2755 err = PTR_ERR(mod);
2756 goto free_copy;
2759 /* Now module is in final location, initialize linked lists, etc. */
2760 err = module_unload_init(mod);
2761 if (err)
2762 goto free_module;
2764 /* Now we've got everything in the final locations, we can
2765 * find optional sections. */
2766 find_module_sections(mod, &info);
2768 err = check_module_license_and_versions(mod);
2769 if (err)
2770 goto free_unload;
2772 /* Set up MODINFO_ATTR fields */
2773 setup_modinfo(mod, &info);
2775 /* Fix up syms, so that st_value is a pointer to location. */
2776 err = simplify_symbols(mod, &info);
2777 if (err < 0)
2778 goto free_modinfo;
2780 err = apply_relocations(mod, &info);
2781 if (err < 0)
2782 goto free_modinfo;
2784 err = post_relocation(mod, &info);
2785 if (err < 0)
2786 goto free_modinfo;
2788 flush_module_icache(mod);
2790 /* Now copy in args */
2791 mod->args = strndup_user(uargs, ~0UL >> 1);
2792 if (IS_ERR(mod->args)) {
2793 err = PTR_ERR(mod->args);
2794 goto free_arch_cleanup;
2797 /* Mark state as coming so strong_try_module_get() ignores us. */
2798 mod->state = MODULE_STATE_COMING;
2800 /* Now sew it into the lists so we can get lockdep and oops
2801 * info during argument parsing. No one should access us, since
2802 * strong_try_module_get() will fail.
2803 * lockdep/oops can run asynchronous, so use the RCU list insertion
2804 * function to insert in a way safe to concurrent readers.
2805 * The mutex protects against concurrent writers.
2807 mutex_lock(&module_mutex);
2808 if (find_module(mod->name)) {
2809 err = -EEXIST;
2810 goto unlock;
2813 /* This has to be done once we're sure module name is unique. */
2814 if (!mod->taints || mod->taints == (1U<<TAINT_CRAP))
2815 dynamic_debug_setup(info.debug, info.num_debug);
2817 /* Find duplicate symbols */
2818 err = verify_export_symbols(mod);
2819 if (err < 0)
2820 goto ddebug;
2822 module_bug_finalize(info.hdr, info.sechdrs, mod);
2823 list_add_rcu(&mod->list, &modules);
2824 mutex_unlock(&module_mutex);
2826 /* Module is ready to execute: parsing args may do that. */
2827 err = parse_args(mod->name, mod->args, mod->kp, mod->num_kp, NULL);
2828 if (err < 0)
2829 goto unlink;
2831 /* Link in to syfs. */
2832 err = mod_sysfs_setup(mod, &info, mod->kp, mod->num_kp);
2833 if (err < 0)
2834 goto unlink;
2836 /* Get rid of temporary copy and strmap. */
2837 kfree(info.strmap);
2838 free_copy(&info);
2840 /* Done! */
2841 trace_module_load(mod);
2842 return mod;
2844 unlink:
2845 mutex_lock(&module_mutex);
2846 /* Unlink carefully: kallsyms could be walking list. */
2847 list_del_rcu(&mod->list);
2848 module_bug_cleanup(mod);
2850 ddebug:
2851 if (!mod->taints || mod->taints == (1U<<TAINT_CRAP))
2852 dynamic_debug_remove(info.debug);
2853 unlock:
2854 mutex_unlock(&module_mutex);
2855 synchronize_sched();
2856 kfree(mod->args);
2857 free_arch_cleanup:
2858 module_arch_cleanup(mod);
2859 free_modinfo:
2860 free_modinfo(mod);
2861 free_unload:
2862 module_unload_free(mod);
2863 free_module:
2864 module_deallocate(mod, &info);
2865 free_copy:
2866 free_copy(&info);
2867 return ERR_PTR(err);
2870 /* Call module constructors. */
2871 static void do_mod_ctors(struct module *mod)
2873 #ifdef CONFIG_CONSTRUCTORS
2874 unsigned long i;
2876 for (i = 0; i < mod->num_ctors; i++)
2877 mod->ctors[i]();
2878 #endif
2881 /* This is where the real work happens */
2882 SYSCALL_DEFINE3(init_module, void __user *, umod,
2883 unsigned long, len, const char __user *, uargs)
2885 struct module *mod;
2886 int ret = 0;
2888 /* Must have permission */
2889 if (!capable(CAP_SYS_MODULE) || modules_disabled)
2890 return -EPERM;
2892 /* Do all the hard work */
2893 mod = load_module(umod, len, uargs);
2894 if (IS_ERR(mod))
2895 return PTR_ERR(mod);
2897 blocking_notifier_call_chain(&module_notify_list,
2898 MODULE_STATE_COMING, mod);
2900 /* Set RO and NX regions for core */
2901 set_section_ro_nx(mod->module_core,
2902 mod->core_text_size,
2903 mod->core_ro_size,
2904 mod->core_size);
2906 /* Set RO and NX regions for init */
2907 set_section_ro_nx(mod->module_init,
2908 mod->init_text_size,
2909 mod->init_ro_size,
2910 mod->init_size);
2912 do_mod_ctors(mod);
2913 /* Start the module */
2914 if (mod->init != NULL)
2915 ret = do_one_initcall(mod->init);
2916 if (ret < 0) {
2917 /* Init routine failed: abort. Try to protect us from
2918 buggy refcounters. */
2919 mod->state = MODULE_STATE_GOING;
2920 synchronize_sched();
2921 module_put(mod);
2922 blocking_notifier_call_chain(&module_notify_list,
2923 MODULE_STATE_GOING, mod);
2924 free_module(mod);
2925 wake_up(&module_wq);
2926 return ret;
2928 if (ret > 0) {
2929 printk(KERN_WARNING
2930 "%s: '%s'->init suspiciously returned %d, it should follow 0/-E convention\n"
2931 "%s: loading module anyway...\n",
2932 __func__, mod->name, ret,
2933 __func__);
2934 dump_stack();
2937 /* Now it's a first class citizen! Wake up anyone waiting for it. */
2938 mod->state = MODULE_STATE_LIVE;
2939 wake_up(&module_wq);
2940 blocking_notifier_call_chain(&module_notify_list,
2941 MODULE_STATE_LIVE, mod);
2943 /* We need to finish all async code before the module init sequence is done */
2944 async_synchronize_full();
2946 mutex_lock(&module_mutex);
2947 /* Drop initial reference. */
2948 module_put(mod);
2949 trim_init_extable(mod);
2950 #ifdef CONFIG_KALLSYMS
2951 mod->num_symtab = mod->core_num_syms;
2952 mod->symtab = mod->core_symtab;
2953 mod->strtab = mod->core_strtab;
2954 #endif
2955 unset_module_init_ro_nx(mod);
2956 module_free(mod, mod->module_init);
2957 mod->module_init = NULL;
2958 mod->init_size = 0;
2959 mod->init_ro_size = 0;
2960 mod->init_text_size = 0;
2961 mutex_unlock(&module_mutex);
2963 return 0;
2966 static inline int within(unsigned long addr, void *start, unsigned long size)
2968 return ((void *)addr >= start && (void *)addr < start + size);
2971 #ifdef CONFIG_KALLSYMS
2973 * This ignores the intensely annoying "mapping symbols" found
2974 * in ARM ELF files: $a, $t and $d.
2976 static inline int is_arm_mapping_symbol(const char *str)
2978 return str[0] == '$' && strchr("atd", str[1])
2979 && (str[2] == '\0' || str[2] == '.');
2982 static const char *get_ksymbol(struct module *mod,
2983 unsigned long addr,
2984 unsigned long *size,
2985 unsigned long *offset)
2987 unsigned int i, best = 0;
2988 unsigned long nextval;
2990 /* At worse, next value is at end of module */
2991 if (within_module_init(addr, mod))
2992 nextval = (unsigned long)mod->module_init+mod->init_text_size;
2993 else
2994 nextval = (unsigned long)mod->module_core+mod->core_text_size;
2996 /* Scan for closest preceding symbol, and next symbol. (ELF
2997 starts real symbols at 1). */
2998 for (i = 1; i < mod->num_symtab; i++) {
2999 if (mod->symtab[i].st_shndx == SHN_UNDEF)
3000 continue;
3002 /* We ignore unnamed symbols: they're uninformative
3003 * and inserted at a whim. */
3004 if (mod->symtab[i].st_value <= addr
3005 && mod->symtab[i].st_value > mod->symtab[best].st_value
3006 && *(mod->strtab + mod->symtab[i].st_name) != '\0'
3007 && !is_arm_mapping_symbol(mod->strtab + mod->symtab[i].st_name))
3008 best = i;
3009 if (mod->symtab[i].st_value > addr
3010 && mod->symtab[i].st_value < nextval
3011 && *(mod->strtab + mod->symtab[i].st_name) != '\0'
3012 && !is_arm_mapping_symbol(mod->strtab + mod->symtab[i].st_name))
3013 nextval = mod->symtab[i].st_value;
3016 if (!best)
3017 return NULL;
3019 if (size)
3020 *size = nextval - mod->symtab[best].st_value;
3021 if (offset)
3022 *offset = addr - mod->symtab[best].st_value;
3023 return mod->strtab + mod->symtab[best].st_name;
3026 /* For kallsyms to ask for address resolution. NULL means not found. Careful
3027 * not to lock to avoid deadlock on oopses, simply disable preemption. */
3028 const char *module_address_lookup(unsigned long addr,
3029 unsigned long *size,
3030 unsigned long *offset,
3031 char **modname,
3032 char *namebuf)
3034 struct module *mod;
3035 const char *ret = NULL;
3037 preempt_disable();
3038 list_for_each_entry_rcu(mod, &modules, list) {
3039 if (within_module_init(addr, mod) ||
3040 within_module_core(addr, mod)) {
3041 if (modname)
3042 *modname = mod->name;
3043 ret = get_ksymbol(mod, addr, size, offset);
3044 break;
3047 /* Make a copy in here where it's safe */
3048 if (ret) {
3049 strncpy(namebuf, ret, KSYM_NAME_LEN - 1);
3050 ret = namebuf;
3052 preempt_enable();
3053 return ret;
3056 int lookup_module_symbol_name(unsigned long addr, char *symname)
3058 struct module *mod;
3060 preempt_disable();
3061 list_for_each_entry_rcu(mod, &modules, list) {
3062 if (within_module_init(addr, mod) ||
3063 within_module_core(addr, mod)) {
3064 const char *sym;
3066 sym = get_ksymbol(mod, addr, NULL, NULL);
3067 if (!sym)
3068 goto out;
3069 strlcpy(symname, sym, KSYM_NAME_LEN);
3070 preempt_enable();
3071 return 0;
3074 out:
3075 preempt_enable();
3076 return -ERANGE;
3079 int lookup_module_symbol_attrs(unsigned long addr, unsigned long *size,
3080 unsigned long *offset, char *modname, char *name)
3082 struct module *mod;
3084 preempt_disable();
3085 list_for_each_entry_rcu(mod, &modules, list) {
3086 if (within_module_init(addr, mod) ||
3087 within_module_core(addr, mod)) {
3088 const char *sym;
3090 sym = get_ksymbol(mod, addr, size, offset);
3091 if (!sym)
3092 goto out;
3093 if (modname)
3094 strlcpy(modname, mod->name, MODULE_NAME_LEN);
3095 if (name)
3096 strlcpy(name, sym, KSYM_NAME_LEN);
3097 preempt_enable();
3098 return 0;
3101 out:
3102 preempt_enable();
3103 return -ERANGE;
3106 int module_get_kallsym(unsigned int symnum, unsigned long *value, char *type,
3107 char *name, char *module_name, int *exported)
3109 struct module *mod;
3111 preempt_disable();
3112 list_for_each_entry_rcu(mod, &modules, list) {
3113 if (symnum < mod->num_symtab) {
3114 *value = mod->symtab[symnum].st_value;
3115 *type = mod->symtab[symnum].st_info;
3116 strlcpy(name, mod->strtab + mod->symtab[symnum].st_name,
3117 KSYM_NAME_LEN);
3118 strlcpy(module_name, mod->name, MODULE_NAME_LEN);
3119 *exported = is_exported(name, *value, mod);
3120 preempt_enable();
3121 return 0;
3123 symnum -= mod->num_symtab;
3125 preempt_enable();
3126 return -ERANGE;
3129 static unsigned long mod_find_symname(struct module *mod, const char *name)
3131 unsigned int i;
3133 for (i = 0; i < mod->num_symtab; i++)
3134 if (strcmp(name, mod->strtab+mod->symtab[i].st_name) == 0 &&
3135 mod->symtab[i].st_info != 'U')
3136 return mod->symtab[i].st_value;
3137 return 0;
3140 /* Look for this name: can be of form module:name. */
3141 unsigned long module_kallsyms_lookup_name(const char *name)
3143 struct module *mod;
3144 char *colon;
3145 unsigned long ret = 0;
3147 /* Don't lock: we're in enough trouble already. */
3148 preempt_disable();
3149 if ((colon = strchr(name, ':')) != NULL) {
3150 *colon = '\0';
3151 if ((mod = find_module(name)) != NULL)
3152 ret = mod_find_symname(mod, colon+1);
3153 *colon = ':';
3154 } else {
3155 list_for_each_entry_rcu(mod, &modules, list)
3156 if ((ret = mod_find_symname(mod, name)) != 0)
3157 break;
3159 preempt_enable();
3160 return ret;
3163 int module_kallsyms_on_each_symbol(int (*fn)(void *, const char *,
3164 struct module *, unsigned long),
3165 void *data)
3167 struct module *mod;
3168 unsigned int i;
3169 int ret;
3171 list_for_each_entry(mod, &modules, list) {
3172 for (i = 0; i < mod->num_symtab; i++) {
3173 ret = fn(data, mod->strtab + mod->symtab[i].st_name,
3174 mod, mod->symtab[i].st_value);
3175 if (ret != 0)
3176 return ret;
3179 return 0;
3181 #endif /* CONFIG_KALLSYMS */
3183 static char *module_flags(struct module *mod, char *buf)
3185 int bx = 0;
3187 if (mod->taints ||
3188 mod->state == MODULE_STATE_GOING ||
3189 mod->state == MODULE_STATE_COMING) {
3190 buf[bx++] = '(';
3191 if (mod->taints & (1 << TAINT_PROPRIETARY_MODULE))
3192 buf[bx++] = 'P';
3193 if (mod->taints & (1 << TAINT_FORCED_MODULE))
3194 buf[bx++] = 'F';
3195 if (mod->taints & (1 << TAINT_CRAP))
3196 buf[bx++] = 'C';
3198 * TAINT_FORCED_RMMOD: could be added.
3199 * TAINT_UNSAFE_SMP, TAINT_MACHINE_CHECK, TAINT_BAD_PAGE don't
3200 * apply to modules.
3203 /* Show a - for module-is-being-unloaded */
3204 if (mod->state == MODULE_STATE_GOING)
3205 buf[bx++] = '-';
3206 /* Show a + for module-is-being-loaded */
3207 if (mod->state == MODULE_STATE_COMING)
3208 buf[bx++] = '+';
3209 buf[bx++] = ')';
3211 buf[bx] = '\0';
3213 return buf;
3216 #ifdef CONFIG_PROC_FS
3217 /* Called by the /proc file system to return a list of modules. */
3218 static void *m_start(struct seq_file *m, loff_t *pos)
3220 mutex_lock(&module_mutex);
3221 return seq_list_start(&modules, *pos);
3224 static void *m_next(struct seq_file *m, void *p, loff_t *pos)
3226 return seq_list_next(p, &modules, pos);
3229 static void m_stop(struct seq_file *m, void *p)
3231 mutex_unlock(&module_mutex);
3234 static int m_show(struct seq_file *m, void *p)
3236 struct module *mod = list_entry(p, struct module, list);
3237 char buf[8];
3239 seq_printf(m, "%s %u",
3240 mod->name, mod->init_size + mod->core_size);
3241 print_unload_info(m, mod);
3243 /* Informative for users. */
3244 seq_printf(m, " %s",
3245 mod->state == MODULE_STATE_GOING ? "Unloading":
3246 mod->state == MODULE_STATE_COMING ? "Loading":
3247 "Live");
3248 /* Used by oprofile and other similar tools. */
3249 seq_printf(m, " 0x%pK", mod->module_core);
3251 /* Taints info */
3252 if (mod->taints)
3253 seq_printf(m, " %s", module_flags(mod, buf));
3255 seq_printf(m, "\n");
3256 return 0;
3259 /* Format: modulename size refcount deps address
3261 Where refcount is a number or -, and deps is a comma-separated list
3262 of depends or -.
3264 static const struct seq_operations modules_op = {
3265 .start = m_start,
3266 .next = m_next,
3267 .stop = m_stop,
3268 .show = m_show
3271 static int modules_open(struct inode *inode, struct file *file)
3273 return seq_open(file, &modules_op);
3276 static const struct file_operations proc_modules_operations = {
3277 .open = modules_open,
3278 .read = seq_read,
3279 .llseek = seq_lseek,
3280 .release = seq_release,
3283 static int __init proc_modules_init(void)
3285 proc_create("modules", 0, NULL, &proc_modules_operations);
3286 return 0;
3288 module_init(proc_modules_init);
3289 #endif
3291 /* Given an address, look for it in the module exception tables. */
3292 const struct exception_table_entry *search_module_extables(unsigned long addr)
3294 const struct exception_table_entry *e = NULL;
3295 struct module *mod;
3297 preempt_disable();
3298 list_for_each_entry_rcu(mod, &modules, list) {
3299 if (mod->num_exentries == 0)
3300 continue;
3302 e = search_extable(mod->extable,
3303 mod->extable + mod->num_exentries - 1,
3304 addr);
3305 if (e)
3306 break;
3308 preempt_enable();
3310 /* Now, if we found one, we are running inside it now, hence
3311 we cannot unload the module, hence no refcnt needed. */
3312 return e;
3316 * is_module_address - is this address inside a module?
3317 * @addr: the address to check.
3319 * See is_module_text_address() if you simply want to see if the address
3320 * is code (not data).
3322 bool is_module_address(unsigned long addr)
3324 bool ret;
3326 preempt_disable();
3327 ret = __module_address(addr) != NULL;
3328 preempt_enable();
3330 return ret;
3334 * __module_address - get the module which contains an address.
3335 * @addr: the address.
3337 * Must be called with preempt disabled or module mutex held so that
3338 * module doesn't get freed during this.
3340 struct module *__module_address(unsigned long addr)
3342 struct module *mod;
3344 if (addr < module_addr_min || addr > module_addr_max)
3345 return NULL;
3347 list_for_each_entry_rcu(mod, &modules, list)
3348 if (within_module_core(addr, mod)
3349 || within_module_init(addr, mod))
3350 return mod;
3351 return NULL;
3353 EXPORT_SYMBOL_GPL(__module_address);
3356 * is_module_text_address - is this address inside module code?
3357 * @addr: the address to check.
3359 * See is_module_address() if you simply want to see if the address is
3360 * anywhere in a module. See kernel_text_address() for testing if an
3361 * address corresponds to kernel or module code.
3363 bool is_module_text_address(unsigned long addr)
3365 bool ret;
3367 preempt_disable();
3368 ret = __module_text_address(addr) != NULL;
3369 preempt_enable();
3371 return ret;
3375 * __module_text_address - get the module whose code contains an address.
3376 * @addr: the address.
3378 * Must be called with preempt disabled or module mutex held so that
3379 * module doesn't get freed during this.
3381 struct module *__module_text_address(unsigned long addr)
3383 struct module *mod = __module_address(addr);
3384 if (mod) {
3385 /* Make sure it's within the text section. */
3386 if (!within(addr, mod->module_init, mod->init_text_size)
3387 && !within(addr, mod->module_core, mod->core_text_size))
3388 mod = NULL;
3390 return mod;
3392 EXPORT_SYMBOL_GPL(__module_text_address);
3394 /* Don't grab lock, we're oopsing. */
3395 void print_modules(void)
3397 struct module *mod;
3398 char buf[8];
3400 printk(KERN_DEFAULT "Modules linked in:");
3401 /* Most callers should already have preempt disabled, but make sure */
3402 preempt_disable();
3403 list_for_each_entry_rcu(mod, &modules, list)
3404 printk(" %s%s", mod->name, module_flags(mod, buf));
3405 preempt_enable();
3406 if (last_unloaded_module[0])
3407 printk(" [last unloaded: %s]", last_unloaded_module);
3408 printk("\n");
3411 #ifdef CONFIG_MODVERSIONS
3412 /* Generate the signature for all relevant module structures here.
3413 * If these change, we don't want to try to parse the module. */
3414 void module_layout(struct module *mod,
3415 struct modversion_info *ver,
3416 struct kernel_param *kp,
3417 struct kernel_symbol *ks,
3418 struct tracepoint * const *tp)
3421 EXPORT_SYMBOL(module_layout);
3422 #endif
3424 #ifdef CONFIG_TRACEPOINTS
3425 void module_update_tracepoints(void)
3427 struct module *mod;
3429 mutex_lock(&module_mutex);
3430 list_for_each_entry(mod, &modules, list)
3431 if (!mod->taints)
3432 tracepoint_update_probe_range(mod->tracepoints_ptrs,
3433 mod->tracepoints_ptrs + mod->num_tracepoints);
3434 mutex_unlock(&module_mutex);
3438 * Returns 0 if current not found.
3439 * Returns 1 if current found.
3441 int module_get_iter_tracepoints(struct tracepoint_iter *iter)
3443 struct module *iter_mod;
3444 int found = 0;
3446 mutex_lock(&module_mutex);
3447 list_for_each_entry(iter_mod, &modules, list) {
3448 if (!iter_mod->taints) {
3450 * Sorted module list
3452 if (iter_mod < iter->module)
3453 continue;
3454 else if (iter_mod > iter->module)
3455 iter->tracepoint = NULL;
3456 found = tracepoint_get_iter_range(&iter->tracepoint,
3457 iter_mod->tracepoints_ptrs,
3458 iter_mod->tracepoints_ptrs
3459 + iter_mod->num_tracepoints);
3460 if (found) {
3461 iter->module = iter_mod;
3462 break;
3466 mutex_unlock(&module_mutex);
3467 return found;
3469 #endif