2 Copyright (C) 2002 Richard Henderson
3 Copyright (C) 2001 Rusty Russell, 2002, 2010 Rusty Russell IBM.
5 This program is free software; you can redistribute it and/or modify
6 it under the terms of the GNU General Public License as published by
7 the Free Software Foundation; either version 2 of the License, or
8 (at your option) any later version.
10 This program is distributed in the hope that it will be useful,
11 but WITHOUT ANY WARRANTY; without even the implied warranty of
12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
13 GNU General Public License for more details.
15 You should have received a copy of the GNU General Public License
16 along with this program; if not, write to the Free Software
17 Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
19 #include <linux/export.h>
20 #include <linux/moduleloader.h>
21 #include <linux/ftrace_event.h>
22 #include <linux/init.h>
23 #include <linux/kallsyms.h>
25 #include <linux/sysfs.h>
26 #include <linux/kernel.h>
27 #include <linux/slab.h>
28 #include <linux/vmalloc.h>
29 #include <linux/elf.h>
30 #include <linux/proc_fs.h>
31 #include <linux/seq_file.h>
32 #include <linux/syscalls.h>
33 #include <linux/fcntl.h>
34 #include <linux/rcupdate.h>
35 #include <linux/capability.h>
36 #include <linux/cpu.h>
37 #include <linux/moduleparam.h>
38 #include <linux/errno.h>
39 #include <linux/err.h>
40 #include <linux/vermagic.h>
41 #include <linux/notifier.h>
42 #include <linux/sched.h>
43 #include <linux/stop_machine.h>
44 #include <linux/device.h>
45 #include <linux/string.h>
46 #include <linux/mutex.h>
47 #include <linux/rculist.h>
48 #include <asm/uaccess.h>
49 #include <asm/cacheflush.h>
50 #include <asm/mmu_context.h>
51 #include <linux/license.h>
52 #include <asm/sections.h>
53 #include <linux/tracepoint.h>
54 #include <linux/ftrace.h>
55 #include <linux/async.h>
56 #include <linux/percpu.h>
57 #include <linux/kmemleak.h>
58 #include <linux/jump_label.h>
59 #include <linux/pfn.h>
60 #include <linux/bsearch.h>
62 #define CREATE_TRACE_POINTS
63 #include <trace/events/module.h>
65 #ifndef ARCH_SHF_SMALL
66 #define ARCH_SHF_SMALL 0
70 * Modules' sections will be aligned on page boundaries
71 * to ensure complete separation of code and data, but
72 * only when CONFIG_DEBUG_SET_MODULE_RONX=y
74 #ifdef CONFIG_DEBUG_SET_MODULE_RONX
75 # define debug_align(X) ALIGN(X, PAGE_SIZE)
77 # define debug_align(X) (X)
81 * Given BASE and SIZE this macro calculates the number of pages the
82 * memory regions occupies
84 #define MOD_NUMBER_OF_PAGES(BASE, SIZE) (((SIZE) > 0) ? \
85 (PFN_DOWN((unsigned long)(BASE) + (SIZE) - 1) - \
86 PFN_DOWN((unsigned long)BASE) + 1) \
89 /* If this is set, the section belongs in the init part of the module */
90 #define INIT_OFFSET_MASK (1UL << (BITS_PER_LONG-1))
94 * 1) List of modules (also safely readable with preempt_disable),
95 * 2) module_use links,
96 * 3) module_addr_min/module_addr_max.
97 * (delete uses stop_machine/add uses RCU list operations). */
98 DEFINE_MUTEX(module_mutex);
99 EXPORT_SYMBOL_GPL(module_mutex);
100 static LIST_HEAD(modules);
101 #ifdef CONFIG_KGDB_KDB
102 struct list_head *kdb_modules = &modules; /* kdb needs the list of modules */
103 #endif /* CONFIG_KGDB_KDB */
106 /* Block module loading/unloading? */
107 int modules_disabled = 0;
108 core_param(nomodule, modules_disabled, bint, 0);
110 /* Waiting for a module to finish initializing? */
111 static DECLARE_WAIT_QUEUE_HEAD(module_wq);
113 static BLOCKING_NOTIFIER_HEAD(module_notify_list);
115 /* Bounds of module allocation, for speeding __module_address.
116 * Protected by module_mutex. */
117 static unsigned long module_addr_min = -1UL, module_addr_max = 0;
119 int register_module_notifier(struct notifier_block * nb)
121 return blocking_notifier_chain_register(&module_notify_list, nb);
123 EXPORT_SYMBOL(register_module_notifier);
125 int unregister_module_notifier(struct notifier_block * nb)
127 return blocking_notifier_chain_unregister(&module_notify_list, nb);
129 EXPORT_SYMBOL(unregister_module_notifier);
135 char *secstrings, *strtab;
136 unsigned long symoffs, stroffs;
137 struct _ddebug *debug;
138 unsigned int num_debug;
140 unsigned int sym, str, mod, vers, info, pcpu;
144 /* We require a truly strong try_module_get(): 0 means failure due to
145 ongoing or failed initialization etc. */
146 static inline int strong_try_module_get(struct module *mod)
148 if (mod && mod->state == MODULE_STATE_COMING)
150 if (try_module_get(mod))
156 static inline void add_taint_module(struct module *mod, unsigned flag)
159 mod->taints |= (1U << flag);
163 * A thread that wants to hold a reference to a module only while it
164 * is running can call this to safely exit. nfsd and lockd use this.
166 void __module_put_and_exit(struct module *mod, long code)
171 EXPORT_SYMBOL(__module_put_and_exit);
173 /* Find a module section: 0 means not found. */
174 static unsigned int find_sec(const struct load_info *info, const char *name)
178 for (i = 1; i < info->hdr->e_shnum; i++) {
179 Elf_Shdr *shdr = &info->sechdrs[i];
180 /* Alloc bit cleared means "ignore it." */
181 if ((shdr->sh_flags & SHF_ALLOC)
182 && strcmp(info->secstrings + shdr->sh_name, name) == 0)
188 /* Find a module section, or NULL. */
189 static void *section_addr(const struct load_info *info, const char *name)
191 /* Section 0 has sh_addr 0. */
192 return (void *)info->sechdrs[find_sec(info, name)].sh_addr;
195 /* Find a module section, or NULL. Fill in number of "objects" in section. */
196 static void *section_objs(const struct load_info *info,
201 unsigned int sec = find_sec(info, name);
203 /* Section 0 has sh_addr 0 and sh_size 0. */
204 *num = info->sechdrs[sec].sh_size / object_size;
205 return (void *)info->sechdrs[sec].sh_addr;
208 /* Provided by the linker */
209 extern const struct kernel_symbol __start___ksymtab[];
210 extern const struct kernel_symbol __stop___ksymtab[];
211 extern const struct kernel_symbol __start___ksymtab_gpl[];
212 extern const struct kernel_symbol __stop___ksymtab_gpl[];
213 extern const struct kernel_symbol __start___ksymtab_gpl_future[];
214 extern const struct kernel_symbol __stop___ksymtab_gpl_future[];
215 extern const unsigned long __start___kcrctab[];
216 extern const unsigned long __start___kcrctab_gpl[];
217 extern const unsigned long __start___kcrctab_gpl_future[];
218 #ifdef CONFIG_UNUSED_SYMBOLS
219 extern const struct kernel_symbol __start___ksymtab_unused[];
220 extern const struct kernel_symbol __stop___ksymtab_unused[];
221 extern const struct kernel_symbol __start___ksymtab_unused_gpl[];
222 extern const struct kernel_symbol __stop___ksymtab_unused_gpl[];
223 extern const unsigned long __start___kcrctab_unused[];
224 extern const unsigned long __start___kcrctab_unused_gpl[];
227 #ifndef CONFIG_MODVERSIONS
228 #define symversion(base, idx) NULL
230 #define symversion(base, idx) ((base != NULL) ? ((base) + (idx)) : NULL)
233 static bool each_symbol_in_section(const struct symsearch *arr,
234 unsigned int arrsize,
235 struct module *owner,
236 bool (*fn)(const struct symsearch *syms,
237 struct module *owner,
243 for (j = 0; j < arrsize; j++) {
244 if (fn(&arr[j], owner, data))
251 /* Returns true as soon as fn returns true, otherwise false. */
252 bool each_symbol_section(bool (*fn)(const struct symsearch *arr,
253 struct module *owner,
258 static const struct symsearch arr[] = {
259 { __start___ksymtab, __stop___ksymtab, __start___kcrctab,
260 NOT_GPL_ONLY, false },
261 { __start___ksymtab_gpl, __stop___ksymtab_gpl,
262 __start___kcrctab_gpl,
264 { __start___ksymtab_gpl_future, __stop___ksymtab_gpl_future,
265 __start___kcrctab_gpl_future,
266 WILL_BE_GPL_ONLY, false },
267 #ifdef CONFIG_UNUSED_SYMBOLS
268 { __start___ksymtab_unused, __stop___ksymtab_unused,
269 __start___kcrctab_unused,
270 NOT_GPL_ONLY, true },
271 { __start___ksymtab_unused_gpl, __stop___ksymtab_unused_gpl,
272 __start___kcrctab_unused_gpl,
277 if (each_symbol_in_section(arr, ARRAY_SIZE(arr), NULL, fn, data))
280 list_for_each_entry_rcu(mod, &modules, list) {
281 struct symsearch arr[] = {
282 { mod->syms, mod->syms + mod->num_syms, mod->crcs,
283 NOT_GPL_ONLY, false },
284 { mod->gpl_syms, mod->gpl_syms + mod->num_gpl_syms,
287 { mod->gpl_future_syms,
288 mod->gpl_future_syms + mod->num_gpl_future_syms,
289 mod->gpl_future_crcs,
290 WILL_BE_GPL_ONLY, false },
291 #ifdef CONFIG_UNUSED_SYMBOLS
293 mod->unused_syms + mod->num_unused_syms,
295 NOT_GPL_ONLY, true },
296 { mod->unused_gpl_syms,
297 mod->unused_gpl_syms + mod->num_unused_gpl_syms,
298 mod->unused_gpl_crcs,
303 if (each_symbol_in_section(arr, ARRAY_SIZE(arr), mod, fn, data))
308 EXPORT_SYMBOL_GPL(each_symbol_section);
310 struct find_symbol_arg {
317 struct module *owner;
318 const unsigned long *crc;
319 const struct kernel_symbol *sym;
322 static bool check_symbol(const struct symsearch *syms,
323 struct module *owner,
324 unsigned int symnum, void *data)
326 struct find_symbol_arg *fsa = data;
329 if (syms->licence == GPL_ONLY)
331 if (syms->licence == WILL_BE_GPL_ONLY && fsa->warn) {
332 printk(KERN_WARNING "Symbol %s is being used "
333 "by a non-GPL module, which will not "
334 "be allowed in the future\n", fsa->name);
335 printk(KERN_WARNING "Please see the file "
336 "Documentation/feature-removal-schedule.txt "
337 "in the kernel source tree for more details.\n");
341 #ifdef CONFIG_UNUSED_SYMBOLS
342 if (syms->unused && fsa->warn) {
343 printk(KERN_WARNING "Symbol %s is marked as UNUSED, "
344 "however this module is using it.\n", fsa->name);
346 "This symbol will go away in the future.\n");
348 "Please evalute if this is the right api to use and if "
349 "it really is, submit a report the linux kernel "
350 "mailinglist together with submitting your code for "
356 fsa->crc = symversion(syms->crcs, symnum);
357 fsa->sym = &syms->start[symnum];
361 static int cmp_name(const void *va, const void *vb)
364 const struct kernel_symbol *b;
366 return strcmp(a, b->name);
369 static bool find_symbol_in_section(const struct symsearch *syms,
370 struct module *owner,
373 struct find_symbol_arg *fsa = data;
374 struct kernel_symbol *sym;
376 sym = bsearch(fsa->name, syms->start, syms->stop - syms->start,
377 sizeof(struct kernel_symbol), cmp_name);
379 if (sym != NULL && check_symbol(syms, owner, sym - syms->start, data))
385 /* Find a symbol and return it, along with, (optional) crc and
386 * (optional) module which owns it. Needs preempt disabled or module_mutex. */
387 const struct kernel_symbol *find_symbol(const char *name,
388 struct module **owner,
389 const unsigned long **crc,
393 struct find_symbol_arg fsa;
399 if (each_symbol_section(find_symbol_in_section, &fsa)) {
407 pr_debug("Failed to find symbol %s\n", name);
410 EXPORT_SYMBOL_GPL(find_symbol);
412 /* Search for module by name: must hold module_mutex. */
413 struct module *find_module(const char *name)
417 list_for_each_entry(mod, &modules, list) {
418 if (strcmp(mod->name, name) == 0)
423 EXPORT_SYMBOL_GPL(find_module);
427 static inline void __percpu *mod_percpu(struct module *mod)
432 static int percpu_modalloc(struct module *mod,
433 unsigned long size, unsigned long align)
435 if (align > PAGE_SIZE) {
436 printk(KERN_WARNING "%s: per-cpu alignment %li > %li\n",
437 mod->name, align, PAGE_SIZE);
441 mod->percpu = __alloc_reserved_percpu(size, align);
444 "%s: Could not allocate %lu bytes percpu data\n",
448 mod->percpu_size = size;
452 static void percpu_modfree(struct module *mod)
454 free_percpu(mod->percpu);
457 static unsigned int find_pcpusec(struct load_info *info)
459 return find_sec(info, ".data..percpu");
462 static void percpu_modcopy(struct module *mod,
463 const void *from, unsigned long size)
467 for_each_possible_cpu(cpu)
468 memcpy(per_cpu_ptr(mod->percpu, cpu), from, size);
472 * is_module_percpu_address - test whether address is from module static percpu
473 * @addr: address to test
475 * Test whether @addr belongs to module static percpu area.
478 * %true if @addr is from module static percpu area
480 bool is_module_percpu_address(unsigned long addr)
487 list_for_each_entry_rcu(mod, &modules, list) {
488 if (!mod->percpu_size)
490 for_each_possible_cpu(cpu) {
491 void *start = per_cpu_ptr(mod->percpu, cpu);
493 if ((void *)addr >= start &&
494 (void *)addr < start + mod->percpu_size) {
505 #else /* ... !CONFIG_SMP */
507 static inline void __percpu *mod_percpu(struct module *mod)
511 static inline int percpu_modalloc(struct module *mod,
512 unsigned long size, unsigned long align)
516 static inline void percpu_modfree(struct module *mod)
519 static unsigned int find_pcpusec(struct load_info *info)
523 static inline void percpu_modcopy(struct module *mod,
524 const void *from, unsigned long size)
526 /* pcpusec should be 0, and size of that section should be 0. */
529 bool is_module_percpu_address(unsigned long addr)
534 #endif /* CONFIG_SMP */
536 #define MODINFO_ATTR(field) \
537 static void setup_modinfo_##field(struct module *mod, const char *s) \
539 mod->field = kstrdup(s, GFP_KERNEL); \
541 static ssize_t show_modinfo_##field(struct module_attribute *mattr, \
542 struct module_kobject *mk, char *buffer) \
544 return sprintf(buffer, "%s\n", mk->mod->field); \
546 static int modinfo_##field##_exists(struct module *mod) \
548 return mod->field != NULL; \
550 static void free_modinfo_##field(struct module *mod) \
555 static struct module_attribute modinfo_##field = { \
556 .attr = { .name = __stringify(field), .mode = 0444 }, \
557 .show = show_modinfo_##field, \
558 .setup = setup_modinfo_##field, \
559 .test = modinfo_##field##_exists, \
560 .free = free_modinfo_##field, \
563 MODINFO_ATTR(version);
564 MODINFO_ATTR(srcversion);
566 static char last_unloaded_module[MODULE_NAME_LEN+1];
568 #ifdef CONFIG_MODULE_UNLOAD
570 EXPORT_TRACEPOINT_SYMBOL(module_get);
572 /* Init the unload section of the module. */
573 static int module_unload_init(struct module *mod)
575 mod->refptr = alloc_percpu(struct module_ref);
579 INIT_LIST_HEAD(&mod->source_list);
580 INIT_LIST_HEAD(&mod->target_list);
582 /* Hold reference count during initialization. */
583 __this_cpu_write(mod->refptr->incs, 1);
584 /* Backwards compatibility macros put refcount during init. */
585 mod->waiter = current;
590 /* Does a already use b? */
591 static int already_uses(struct module *a, struct module *b)
593 struct module_use *use;
595 list_for_each_entry(use, &b->source_list, source_list) {
596 if (use->source == a) {
597 pr_debug("%s uses %s!\n", a->name, b->name);
601 pr_debug("%s does not use %s!\n", a->name, b->name);
607 * - we add 'a' as a "source", 'b' as a "target" of module use
608 * - the module_use is added to the list of 'b' sources (so
609 * 'b' can walk the list to see who sourced them), and of 'a'
610 * targets (so 'a' can see what modules it targets).
612 static int add_module_usage(struct module *a, struct module *b)
614 struct module_use *use;
616 pr_debug("Allocating new usage for %s.\n", a->name);
617 use = kmalloc(sizeof(*use), GFP_ATOMIC);
619 printk(KERN_WARNING "%s: out of memory loading\n", a->name);
625 list_add(&use->source_list, &b->source_list);
626 list_add(&use->target_list, &a->target_list);
630 /* Module a uses b: caller needs module_mutex() */
631 int ref_module(struct module *a, struct module *b)
635 if (b == NULL || already_uses(a, b))
638 /* If module isn't available, we fail. */
639 err = strong_try_module_get(b);
643 err = add_module_usage(a, b);
650 EXPORT_SYMBOL_GPL(ref_module);
652 /* Clear the unload stuff of the module. */
653 static void module_unload_free(struct module *mod)
655 struct module_use *use, *tmp;
657 mutex_lock(&module_mutex);
658 list_for_each_entry_safe(use, tmp, &mod->target_list, target_list) {
659 struct module *i = use->target;
660 pr_debug("%s unusing %s\n", mod->name, i->name);
662 list_del(&use->source_list);
663 list_del(&use->target_list);
666 mutex_unlock(&module_mutex);
668 free_percpu(mod->refptr);
671 #ifdef CONFIG_MODULE_FORCE_UNLOAD
672 static inline int try_force_unload(unsigned int flags)
674 int ret = (flags & O_TRUNC);
676 add_taint(TAINT_FORCED_RMMOD);
680 static inline int try_force_unload(unsigned int flags)
684 #endif /* CONFIG_MODULE_FORCE_UNLOAD */
693 /* Whole machine is stopped with interrupts off when this runs. */
694 static int __try_stop_module(void *_sref)
696 struct stopref *sref = _sref;
698 /* If it's not unused, quit unless we're forcing. */
699 if (module_refcount(sref->mod) != 0) {
700 if (!(*sref->forced = try_force_unload(sref->flags)))
704 /* Mark it as dying. */
705 sref->mod->state = MODULE_STATE_GOING;
709 static int try_stop_module(struct module *mod, int flags, int *forced)
711 if (flags & O_NONBLOCK) {
712 struct stopref sref = { mod, flags, forced };
714 return stop_machine(__try_stop_module, &sref, NULL);
716 /* We don't need to stop the machine for this. */
717 mod->state = MODULE_STATE_GOING;
723 unsigned long module_refcount(struct module *mod)
725 unsigned long incs = 0, decs = 0;
728 for_each_possible_cpu(cpu)
729 decs += per_cpu_ptr(mod->refptr, cpu)->decs;
731 * ensure the incs are added up after the decs.
732 * module_put ensures incs are visible before decs with smp_wmb.
734 * This 2-count scheme avoids the situation where the refcount
735 * for CPU0 is read, then CPU0 increments the module refcount,
736 * then CPU1 drops that refcount, then the refcount for CPU1 is
737 * read. We would record a decrement but not its corresponding
738 * increment so we would see a low count (disaster).
740 * Rare situation? But module_refcount can be preempted, and we
741 * might be tallying up 4096+ CPUs. So it is not impossible.
744 for_each_possible_cpu(cpu)
745 incs += per_cpu_ptr(mod->refptr, cpu)->incs;
748 EXPORT_SYMBOL(module_refcount);
750 /* This exists whether we can unload or not */
751 static void free_module(struct module *mod);
753 static void wait_for_zero_refcount(struct module *mod)
755 /* Since we might sleep for some time, release the mutex first */
756 mutex_unlock(&module_mutex);
758 pr_debug("Looking at refcount...\n");
759 set_current_state(TASK_UNINTERRUPTIBLE);
760 if (module_refcount(mod) == 0)
764 current->state = TASK_RUNNING;
765 mutex_lock(&module_mutex);
768 SYSCALL_DEFINE2(delete_module, const char __user *, name_user,
772 char name[MODULE_NAME_LEN];
775 if (!capable(CAP_SYS_MODULE) || modules_disabled)
778 if (strncpy_from_user(name, name_user, MODULE_NAME_LEN-1) < 0)
780 name[MODULE_NAME_LEN-1] = '\0';
782 if (mutex_lock_interruptible(&module_mutex) != 0)
785 mod = find_module(name);
791 if (!list_empty(&mod->source_list)) {
792 /* Other modules depend on us: get rid of them first. */
797 /* Doing init or already dying? */
798 if (mod->state != MODULE_STATE_LIVE) {
799 /* FIXME: if (force), slam module count and wake up
801 pr_debug("%s already dying\n", mod->name);
806 /* If it has an init func, it must have an exit func to unload */
807 if (mod->init && !mod->exit) {
808 forced = try_force_unload(flags);
810 /* This module can't be removed */
816 /* Set this up before setting mod->state */
817 mod->waiter = current;
819 /* Stop the machine so refcounts can't move and disable module. */
820 ret = try_stop_module(mod, flags, &forced);
824 /* Never wait if forced. */
825 if (!forced && module_refcount(mod) != 0)
826 wait_for_zero_refcount(mod);
828 mutex_unlock(&module_mutex);
829 /* Final destruction now no one is using it. */
830 if (mod->exit != NULL)
832 blocking_notifier_call_chain(&module_notify_list,
833 MODULE_STATE_GOING, mod);
834 async_synchronize_full();
836 /* Store the name of the last unloaded module for diagnostic purposes */
837 strlcpy(last_unloaded_module, mod->name, sizeof(last_unloaded_module));
842 mutex_unlock(&module_mutex);
846 static inline void print_unload_info(struct seq_file *m, struct module *mod)
848 struct module_use *use;
849 int printed_something = 0;
851 seq_printf(m, " %lu ", module_refcount(mod));
853 /* Always include a trailing , so userspace can differentiate
854 between this and the old multi-field proc format. */
855 list_for_each_entry(use, &mod->source_list, source_list) {
856 printed_something = 1;
857 seq_printf(m, "%s,", use->source->name);
860 if (mod->init != NULL && mod->exit == NULL) {
861 printed_something = 1;
862 seq_printf(m, "[permanent],");
865 if (!printed_something)
869 void __symbol_put(const char *symbol)
871 struct module *owner;
874 if (!find_symbol(symbol, &owner, NULL, true, false))
879 EXPORT_SYMBOL(__symbol_put);
881 /* Note this assumes addr is a function, which it currently always is. */
882 void symbol_put_addr(void *addr)
884 struct module *modaddr;
885 unsigned long a = (unsigned long)dereference_function_descriptor(addr);
887 if (core_kernel_text(a))
890 /* module_text_address is safe here: we're supposed to have reference
891 * to module from symbol_get, so it can't go away. */
892 modaddr = __module_text_address(a);
896 EXPORT_SYMBOL_GPL(symbol_put_addr);
898 static ssize_t show_refcnt(struct module_attribute *mattr,
899 struct module_kobject *mk, char *buffer)
901 return sprintf(buffer, "%lu\n", module_refcount(mk->mod));
904 static struct module_attribute modinfo_refcnt =
905 __ATTR(refcnt, 0444, show_refcnt, NULL);
907 void module_put(struct module *module)
911 smp_wmb(); /* see comment in module_refcount */
912 __this_cpu_inc(module->refptr->decs);
914 trace_module_put(module, _RET_IP_);
915 /* Maybe they're waiting for us to drop reference? */
916 if (unlikely(!module_is_live(module)))
917 wake_up_process(module->waiter);
921 EXPORT_SYMBOL(module_put);
923 #else /* !CONFIG_MODULE_UNLOAD */
924 static inline void print_unload_info(struct seq_file *m, struct module *mod)
926 /* We don't know the usage count, or what modules are using. */
927 seq_printf(m, " - -");
930 static inline void module_unload_free(struct module *mod)
934 int ref_module(struct module *a, struct module *b)
936 return strong_try_module_get(b);
938 EXPORT_SYMBOL_GPL(ref_module);
940 static inline int module_unload_init(struct module *mod)
944 #endif /* CONFIG_MODULE_UNLOAD */
946 static size_t module_flags_taint(struct module *mod, char *buf)
950 if (mod->taints & (1 << TAINT_PROPRIETARY_MODULE))
952 if (mod->taints & (1 << TAINT_OOT_MODULE))
954 if (mod->taints & (1 << TAINT_FORCED_MODULE))
956 if (mod->taints & (1 << TAINT_CRAP))
959 * TAINT_FORCED_RMMOD: could be added.
960 * TAINT_UNSAFE_SMP, TAINT_MACHINE_CHECK, TAINT_BAD_PAGE don't
966 static ssize_t show_initstate(struct module_attribute *mattr,
967 struct module_kobject *mk, char *buffer)
969 const char *state = "unknown";
971 switch (mk->mod->state) {
972 case MODULE_STATE_LIVE:
975 case MODULE_STATE_COMING:
978 case MODULE_STATE_GOING:
982 return sprintf(buffer, "%s\n", state);
985 static struct module_attribute modinfo_initstate =
986 __ATTR(initstate, 0444, show_initstate, NULL);
988 static ssize_t store_uevent(struct module_attribute *mattr,
989 struct module_kobject *mk,
990 const char *buffer, size_t count)
992 enum kobject_action action;
994 if (kobject_action_type(buffer, count, &action) == 0)
995 kobject_uevent(&mk->kobj, action);
999 struct module_attribute module_uevent =
1000 __ATTR(uevent, 0200, NULL, store_uevent);
1002 static ssize_t show_coresize(struct module_attribute *mattr,
1003 struct module_kobject *mk, char *buffer)
1005 return sprintf(buffer, "%u\n", mk->mod->core_size);
1008 static struct module_attribute modinfo_coresize =
1009 __ATTR(coresize, 0444, show_coresize, NULL);
1011 static ssize_t show_initsize(struct module_attribute *mattr,
1012 struct module_kobject *mk, char *buffer)
1014 return sprintf(buffer, "%u\n", mk->mod->init_size);
1017 static struct module_attribute modinfo_initsize =
1018 __ATTR(initsize, 0444, show_initsize, NULL);
1020 static ssize_t show_taint(struct module_attribute *mattr,
1021 struct module_kobject *mk, char *buffer)
1025 l = module_flags_taint(mk->mod, buffer);
1030 static struct module_attribute modinfo_taint =
1031 __ATTR(taint, 0444, show_taint, NULL);
1033 static struct module_attribute *modinfo_attrs[] = {
1036 &modinfo_srcversion,
1041 #ifdef CONFIG_MODULE_UNLOAD
1047 static const char vermagic[] = VERMAGIC_STRING;
1049 static int try_to_force_load(struct module *mod, const char *reason)
1051 #ifdef CONFIG_MODULE_FORCE_LOAD
1052 if (!test_taint(TAINT_FORCED_MODULE))
1053 printk(KERN_WARNING "%s: %s: kernel tainted.\n",
1055 add_taint_module(mod, TAINT_FORCED_MODULE);
1062 #ifdef CONFIG_MODVERSIONS
1063 /* If the arch applies (non-zero) relocations to kernel kcrctab, unapply it. */
1064 static unsigned long maybe_relocated(unsigned long crc,
1065 const struct module *crc_owner)
1067 #ifdef ARCH_RELOCATES_KCRCTAB
1068 if (crc_owner == NULL)
1069 return crc - (unsigned long)reloc_start;
1074 static int check_version(Elf_Shdr *sechdrs,
1075 unsigned int versindex,
1076 const char *symname,
1078 const unsigned long *crc,
1079 const struct module *crc_owner)
1081 unsigned int i, num_versions;
1082 struct modversion_info *versions;
1084 /* Exporting module didn't supply crcs? OK, we're already tainted. */
1088 /* No versions at all? modprobe --force does this. */
1090 return try_to_force_load(mod, symname) == 0;
1092 versions = (void *) sechdrs[versindex].sh_addr;
1093 num_versions = sechdrs[versindex].sh_size
1094 / sizeof(struct modversion_info);
1096 for (i = 0; i < num_versions; i++) {
1097 if (strcmp(versions[i].name, symname) != 0)
1100 if (versions[i].crc == maybe_relocated(*crc, crc_owner))
1102 pr_debug("Found checksum %lX vs module %lX\n",
1103 maybe_relocated(*crc, crc_owner), versions[i].crc);
1107 printk(KERN_WARNING "%s: no symbol version for %s\n",
1108 mod->name, symname);
1112 printk("%s: disagrees about version of symbol %s\n",
1113 mod->name, symname);
1117 static inline int check_modstruct_version(Elf_Shdr *sechdrs,
1118 unsigned int versindex,
1121 const unsigned long *crc;
1123 /* Since this should be found in kernel (which can't be removed),
1124 * no locking is necessary. */
1125 if (!find_symbol(MODULE_SYMBOL_PREFIX "module_layout", NULL,
1128 return check_version(sechdrs, versindex, "module_layout", mod, crc,
1132 /* First part is kernel version, which we ignore if module has crcs. */
1133 static inline int same_magic(const char *amagic, const char *bmagic,
1137 amagic += strcspn(amagic, " ");
1138 bmagic += strcspn(bmagic, " ");
1140 return strcmp(amagic, bmagic) == 0;
1143 static inline int check_version(Elf_Shdr *sechdrs,
1144 unsigned int versindex,
1145 const char *symname,
1147 const unsigned long *crc,
1148 const struct module *crc_owner)
1153 static inline int check_modstruct_version(Elf_Shdr *sechdrs,
1154 unsigned int versindex,
1160 static inline int same_magic(const char *amagic, const char *bmagic,
1163 return strcmp(amagic, bmagic) == 0;
1165 #endif /* CONFIG_MODVERSIONS */
1167 /* Resolve a symbol for this module. I.e. if we find one, record usage. */
1168 static const struct kernel_symbol *resolve_symbol(struct module *mod,
1169 const struct load_info *info,
1173 struct module *owner;
1174 const struct kernel_symbol *sym;
1175 const unsigned long *crc;
1178 mutex_lock(&module_mutex);
1179 sym = find_symbol(name, &owner, &crc,
1180 !(mod->taints & (1 << TAINT_PROPRIETARY_MODULE)), true);
1184 if (!check_version(info->sechdrs, info->index.vers, name, mod, crc,
1186 sym = ERR_PTR(-EINVAL);
1190 err = ref_module(mod, owner);
1197 /* We must make copy under the lock if we failed to get ref. */
1198 strncpy(ownername, module_name(owner), MODULE_NAME_LEN);
1200 mutex_unlock(&module_mutex);
1204 static const struct kernel_symbol *
1205 resolve_symbol_wait(struct module *mod,
1206 const struct load_info *info,
1209 const struct kernel_symbol *ksym;
1210 char owner[MODULE_NAME_LEN];
1212 if (wait_event_interruptible_timeout(module_wq,
1213 !IS_ERR(ksym = resolve_symbol(mod, info, name, owner))
1214 || PTR_ERR(ksym) != -EBUSY,
1216 printk(KERN_WARNING "%s: gave up waiting for init of module %s.\n",
1223 * /sys/module/foo/sections stuff
1224 * J. Corbet <corbet@lwn.net>
1228 #ifdef CONFIG_KALLSYMS
1229 static inline bool sect_empty(const Elf_Shdr *sect)
1231 return !(sect->sh_flags & SHF_ALLOC) || sect->sh_size == 0;
1234 struct module_sect_attr
1236 struct module_attribute mattr;
1238 unsigned long address;
1241 struct module_sect_attrs
1243 struct attribute_group grp;
1244 unsigned int nsections;
1245 struct module_sect_attr attrs[0];
1248 static ssize_t module_sect_show(struct module_attribute *mattr,
1249 struct module_kobject *mk, char *buf)
1251 struct module_sect_attr *sattr =
1252 container_of(mattr, struct module_sect_attr, mattr);
1253 return sprintf(buf, "0x%pK\n", (void *)sattr->address);
1256 static void free_sect_attrs(struct module_sect_attrs *sect_attrs)
1258 unsigned int section;
1260 for (section = 0; section < sect_attrs->nsections; section++)
1261 kfree(sect_attrs->attrs[section].name);
1265 static void add_sect_attrs(struct module *mod, const struct load_info *info)
1267 unsigned int nloaded = 0, i, size[2];
1268 struct module_sect_attrs *sect_attrs;
1269 struct module_sect_attr *sattr;
1270 struct attribute **gattr;
1272 /* Count loaded sections and allocate structures */
1273 for (i = 0; i < info->hdr->e_shnum; i++)
1274 if (!sect_empty(&info->sechdrs[i]))
1276 size[0] = ALIGN(sizeof(*sect_attrs)
1277 + nloaded * sizeof(sect_attrs->attrs[0]),
1278 sizeof(sect_attrs->grp.attrs[0]));
1279 size[1] = (nloaded + 1) * sizeof(sect_attrs->grp.attrs[0]);
1280 sect_attrs = kzalloc(size[0] + size[1], GFP_KERNEL);
1281 if (sect_attrs == NULL)
1284 /* Setup section attributes. */
1285 sect_attrs->grp.name = "sections";
1286 sect_attrs->grp.attrs = (void *)sect_attrs + size[0];
1288 sect_attrs->nsections = 0;
1289 sattr = §_attrs->attrs[0];
1290 gattr = §_attrs->grp.attrs[0];
1291 for (i = 0; i < info->hdr->e_shnum; i++) {
1292 Elf_Shdr *sec = &info->sechdrs[i];
1293 if (sect_empty(sec))
1295 sattr->address = sec->sh_addr;
1296 sattr->name = kstrdup(info->secstrings + sec->sh_name,
1298 if (sattr->name == NULL)
1300 sect_attrs->nsections++;
1301 sysfs_attr_init(&sattr->mattr.attr);
1302 sattr->mattr.show = module_sect_show;
1303 sattr->mattr.store = NULL;
1304 sattr->mattr.attr.name = sattr->name;
1305 sattr->mattr.attr.mode = S_IRUGO;
1306 *(gattr++) = &(sattr++)->mattr.attr;
1310 if (sysfs_create_group(&mod->mkobj.kobj, §_attrs->grp))
1313 mod->sect_attrs = sect_attrs;
1316 free_sect_attrs(sect_attrs);
1319 static void remove_sect_attrs(struct module *mod)
1321 if (mod->sect_attrs) {
1322 sysfs_remove_group(&mod->mkobj.kobj,
1323 &mod->sect_attrs->grp);
1324 /* We are positive that no one is using any sect attrs
1325 * at this point. Deallocate immediately. */
1326 free_sect_attrs(mod->sect_attrs);
1327 mod->sect_attrs = NULL;
1332 * /sys/module/foo/notes/.section.name gives contents of SHT_NOTE sections.
1335 struct module_notes_attrs {
1336 struct kobject *dir;
1338 struct bin_attribute attrs[0];
1341 static ssize_t module_notes_read(struct file *filp, struct kobject *kobj,
1342 struct bin_attribute *bin_attr,
1343 char *buf, loff_t pos, size_t count)
1346 * The caller checked the pos and count against our size.
1348 memcpy(buf, bin_attr->private + pos, count);
1352 static void free_notes_attrs(struct module_notes_attrs *notes_attrs,
1355 if (notes_attrs->dir) {
1357 sysfs_remove_bin_file(notes_attrs->dir,
1358 ¬es_attrs->attrs[i]);
1359 kobject_put(notes_attrs->dir);
1364 static void add_notes_attrs(struct module *mod, const struct load_info *info)
1366 unsigned int notes, loaded, i;
1367 struct module_notes_attrs *notes_attrs;
1368 struct bin_attribute *nattr;
1370 /* failed to create section attributes, so can't create notes */
1371 if (!mod->sect_attrs)
1374 /* Count notes sections and allocate structures. */
1376 for (i = 0; i < info->hdr->e_shnum; i++)
1377 if (!sect_empty(&info->sechdrs[i]) &&
1378 (info->sechdrs[i].sh_type == SHT_NOTE))
1384 notes_attrs = kzalloc(sizeof(*notes_attrs)
1385 + notes * sizeof(notes_attrs->attrs[0]),
1387 if (notes_attrs == NULL)
1390 notes_attrs->notes = notes;
1391 nattr = ¬es_attrs->attrs[0];
1392 for (loaded = i = 0; i < info->hdr->e_shnum; ++i) {
1393 if (sect_empty(&info->sechdrs[i]))
1395 if (info->sechdrs[i].sh_type == SHT_NOTE) {
1396 sysfs_bin_attr_init(nattr);
1397 nattr->attr.name = mod->sect_attrs->attrs[loaded].name;
1398 nattr->attr.mode = S_IRUGO;
1399 nattr->size = info->sechdrs[i].sh_size;
1400 nattr->private = (void *) info->sechdrs[i].sh_addr;
1401 nattr->read = module_notes_read;
1407 notes_attrs->dir = kobject_create_and_add("notes", &mod->mkobj.kobj);
1408 if (!notes_attrs->dir)
1411 for (i = 0; i < notes; ++i)
1412 if (sysfs_create_bin_file(notes_attrs->dir,
1413 ¬es_attrs->attrs[i]))
1416 mod->notes_attrs = notes_attrs;
1420 free_notes_attrs(notes_attrs, i);
1423 static void remove_notes_attrs(struct module *mod)
1425 if (mod->notes_attrs)
1426 free_notes_attrs(mod->notes_attrs, mod->notes_attrs->notes);
1431 static inline void add_sect_attrs(struct module *mod,
1432 const struct load_info *info)
1436 static inline void remove_sect_attrs(struct module *mod)
1440 static inline void add_notes_attrs(struct module *mod,
1441 const struct load_info *info)
1445 static inline void remove_notes_attrs(struct module *mod)
1448 #endif /* CONFIG_KALLSYMS */
1450 static void add_usage_links(struct module *mod)
1452 #ifdef CONFIG_MODULE_UNLOAD
1453 struct module_use *use;
1456 mutex_lock(&module_mutex);
1457 list_for_each_entry(use, &mod->target_list, target_list) {
1458 nowarn = sysfs_create_link(use->target->holders_dir,
1459 &mod->mkobj.kobj, mod->name);
1461 mutex_unlock(&module_mutex);
1465 static void del_usage_links(struct module *mod)
1467 #ifdef CONFIG_MODULE_UNLOAD
1468 struct module_use *use;
1470 mutex_lock(&module_mutex);
1471 list_for_each_entry(use, &mod->target_list, target_list)
1472 sysfs_remove_link(use->target->holders_dir, mod->name);
1473 mutex_unlock(&module_mutex);
1477 static int module_add_modinfo_attrs(struct module *mod)
1479 struct module_attribute *attr;
1480 struct module_attribute *temp_attr;
1484 mod->modinfo_attrs = kzalloc((sizeof(struct module_attribute) *
1485 (ARRAY_SIZE(modinfo_attrs) + 1)),
1487 if (!mod->modinfo_attrs)
1490 temp_attr = mod->modinfo_attrs;
1491 for (i = 0; (attr = modinfo_attrs[i]) && !error; i++) {
1493 (attr->test && attr->test(mod))) {
1494 memcpy(temp_attr, attr, sizeof(*temp_attr));
1495 sysfs_attr_init(&temp_attr->attr);
1496 error = sysfs_create_file(&mod->mkobj.kobj,&temp_attr->attr);
1503 static void module_remove_modinfo_attrs(struct module *mod)
1505 struct module_attribute *attr;
1508 for (i = 0; (attr = &mod->modinfo_attrs[i]); i++) {
1509 /* pick a field to test for end of list */
1510 if (!attr->attr.name)
1512 sysfs_remove_file(&mod->mkobj.kobj,&attr->attr);
1516 kfree(mod->modinfo_attrs);
1519 static int mod_sysfs_init(struct module *mod)
1522 struct kobject *kobj;
1524 if (!module_sysfs_initialized) {
1525 printk(KERN_ERR "%s: module sysfs not initialized\n",
1531 kobj = kset_find_obj(module_kset, mod->name);
1533 printk(KERN_ERR "%s: module is already loaded\n", mod->name);
1539 mod->mkobj.mod = mod;
1541 memset(&mod->mkobj.kobj, 0, sizeof(mod->mkobj.kobj));
1542 mod->mkobj.kobj.kset = module_kset;
1543 err = kobject_init_and_add(&mod->mkobj.kobj, &module_ktype, NULL,
1546 kobject_put(&mod->mkobj.kobj);
1548 /* delay uevent until full sysfs population */
1553 static int mod_sysfs_setup(struct module *mod,
1554 const struct load_info *info,
1555 struct kernel_param *kparam,
1556 unsigned int num_params)
1560 err = mod_sysfs_init(mod);
1564 mod->holders_dir = kobject_create_and_add("holders", &mod->mkobj.kobj);
1565 if (!mod->holders_dir) {
1570 err = module_param_sysfs_setup(mod, kparam, num_params);
1572 goto out_unreg_holders;
1574 err = module_add_modinfo_attrs(mod);
1576 goto out_unreg_param;
1578 add_usage_links(mod);
1579 add_sect_attrs(mod, info);
1580 add_notes_attrs(mod, info);
1582 kobject_uevent(&mod->mkobj.kobj, KOBJ_ADD);
1586 module_param_sysfs_remove(mod);
1588 kobject_put(mod->holders_dir);
1590 kobject_put(&mod->mkobj.kobj);
1595 static void mod_sysfs_fini(struct module *mod)
1597 remove_notes_attrs(mod);
1598 remove_sect_attrs(mod);
1599 kobject_put(&mod->mkobj.kobj);
1602 #else /* !CONFIG_SYSFS */
1604 static int mod_sysfs_setup(struct module *mod,
1605 const struct load_info *info,
1606 struct kernel_param *kparam,
1607 unsigned int num_params)
1612 static void mod_sysfs_fini(struct module *mod)
1616 static void module_remove_modinfo_attrs(struct module *mod)
1620 static void del_usage_links(struct module *mod)
1624 #endif /* CONFIG_SYSFS */
1626 static void mod_sysfs_teardown(struct module *mod)
1628 del_usage_links(mod);
1629 module_remove_modinfo_attrs(mod);
1630 module_param_sysfs_remove(mod);
1631 kobject_put(mod->mkobj.drivers_dir);
1632 kobject_put(mod->holders_dir);
1633 mod_sysfs_fini(mod);
1637 * unlink the module with the whole machine is stopped with interrupts off
1638 * - this defends against kallsyms not taking locks
1640 static int __unlink_module(void *_mod)
1642 struct module *mod = _mod;
1643 list_del(&mod->list);
1644 module_bug_cleanup(mod);
1648 #ifdef CONFIG_DEBUG_SET_MODULE_RONX
1650 * LKM RO/NX protection: protect module's text/ro-data
1651 * from modification and any data from execution.
1653 void set_page_attributes(void *start, void *end, int (*set)(unsigned long start, int num_pages))
1655 unsigned long begin_pfn = PFN_DOWN((unsigned long)start);
1656 unsigned long end_pfn = PFN_DOWN((unsigned long)end);
1658 if (end_pfn > begin_pfn)
1659 set(begin_pfn << PAGE_SHIFT, end_pfn - begin_pfn);
1662 static void set_section_ro_nx(void *base,
1663 unsigned long text_size,
1664 unsigned long ro_size,
1665 unsigned long total_size)
1667 /* begin and end PFNs of the current subsection */
1668 unsigned long begin_pfn;
1669 unsigned long end_pfn;
1672 * Set RO for module text and RO-data:
1673 * - Always protect first page.
1674 * - Do not protect last partial page.
1677 set_page_attributes(base, base + ro_size, set_memory_ro);
1680 * Set NX permissions for module data:
1681 * - Do not protect first partial page.
1682 * - Always protect last page.
1684 if (total_size > text_size) {
1685 begin_pfn = PFN_UP((unsigned long)base + text_size);
1686 end_pfn = PFN_UP((unsigned long)base + total_size);
1687 if (end_pfn > begin_pfn)
1688 set_memory_nx(begin_pfn << PAGE_SHIFT, end_pfn - begin_pfn);
1692 static void unset_module_core_ro_nx(struct module *mod)
1694 set_page_attributes(mod->module_core + mod->core_text_size,
1695 mod->module_core + mod->core_size,
1697 set_page_attributes(mod->module_core,
1698 mod->module_core + mod->core_ro_size,
1702 static void unset_module_init_ro_nx(struct module *mod)
1704 set_page_attributes(mod->module_init + mod->init_text_size,
1705 mod->module_init + mod->init_size,
1707 set_page_attributes(mod->module_init,
1708 mod->module_init + mod->init_ro_size,
1712 /* Iterate through all modules and set each module's text as RW */
1713 void set_all_modules_text_rw(void)
1717 mutex_lock(&module_mutex);
1718 list_for_each_entry_rcu(mod, &modules, list) {
1719 if ((mod->module_core) && (mod->core_text_size)) {
1720 set_page_attributes(mod->module_core,
1721 mod->module_core + mod->core_text_size,
1724 if ((mod->module_init) && (mod->init_text_size)) {
1725 set_page_attributes(mod->module_init,
1726 mod->module_init + mod->init_text_size,
1730 mutex_unlock(&module_mutex);
1733 /* Iterate through all modules and set each module's text as RO */
1734 void set_all_modules_text_ro(void)
1738 mutex_lock(&module_mutex);
1739 list_for_each_entry_rcu(mod, &modules, list) {
1740 if ((mod->module_core) && (mod->core_text_size)) {
1741 set_page_attributes(mod->module_core,
1742 mod->module_core + mod->core_text_size,
1745 if ((mod->module_init) && (mod->init_text_size)) {
1746 set_page_attributes(mod->module_init,
1747 mod->module_init + mod->init_text_size,
1751 mutex_unlock(&module_mutex);
1754 static inline void set_section_ro_nx(void *base, unsigned long text_size, unsigned long ro_size, unsigned long total_size) { }
1755 static void unset_module_core_ro_nx(struct module *mod) { }
1756 static void unset_module_init_ro_nx(struct module *mod) { }
1759 void __weak module_free(struct module *mod, void *module_region)
1761 vfree(module_region);
1764 void __weak module_arch_cleanup(struct module *mod)
1768 /* Free a module, remove from lists, etc. */
1769 static void free_module(struct module *mod)
1771 trace_module_free(mod);
1773 /* Delete from various lists */
1774 mutex_lock(&module_mutex);
1775 stop_machine(__unlink_module, mod, NULL);
1776 mutex_unlock(&module_mutex);
1777 mod_sysfs_teardown(mod);
1779 /* Remove dynamic debug info */
1780 ddebug_remove_module(mod->name);
1782 /* Arch-specific cleanup. */
1783 module_arch_cleanup(mod);
1785 /* Module unload stuff */
1786 module_unload_free(mod);
1788 /* Free any allocated parameters. */
1789 destroy_params(mod->kp, mod->num_kp);
1791 /* This may be NULL, but that's OK */
1792 unset_module_init_ro_nx(mod);
1793 module_free(mod, mod->module_init);
1795 percpu_modfree(mod);
1797 /* Free lock-classes: */
1798 lockdep_free_key_range(mod->module_core, mod->core_size);
1800 /* Finally, free the core (containing the module structure) */
1801 unset_module_core_ro_nx(mod);
1802 module_free(mod, mod->module_core);
1805 update_protections(current->mm);
1809 void *__symbol_get(const char *symbol)
1811 struct module *owner;
1812 const struct kernel_symbol *sym;
1815 sym = find_symbol(symbol, &owner, NULL, true, true);
1816 if (sym && strong_try_module_get(owner))
1820 return sym ? (void *)sym->value : NULL;
1822 EXPORT_SYMBOL_GPL(__symbol_get);
1825 * Ensure that an exported symbol [global namespace] does not already exist
1826 * in the kernel or in some other module's exported symbol table.
1828 * You must hold the module_mutex.
1830 static int verify_export_symbols(struct module *mod)
1833 struct module *owner;
1834 const struct kernel_symbol *s;
1836 const struct kernel_symbol *sym;
1839 { mod->syms, mod->num_syms },
1840 { mod->gpl_syms, mod->num_gpl_syms },
1841 { mod->gpl_future_syms, mod->num_gpl_future_syms },
1842 #ifdef CONFIG_UNUSED_SYMBOLS
1843 { mod->unused_syms, mod->num_unused_syms },
1844 { mod->unused_gpl_syms, mod->num_unused_gpl_syms },
1848 for (i = 0; i < ARRAY_SIZE(arr); i++) {
1849 for (s = arr[i].sym; s < arr[i].sym + arr[i].num; s++) {
1850 if (find_symbol(s->name, &owner, NULL, true, false)) {
1852 "%s: exports duplicate symbol %s"
1854 mod->name, s->name, module_name(owner));
1862 /* Change all symbols so that st_value encodes the pointer directly. */
1863 static int simplify_symbols(struct module *mod, const struct load_info *info)
1865 Elf_Shdr *symsec = &info->sechdrs[info->index.sym];
1866 Elf_Sym *sym = (void *)symsec->sh_addr;
1867 unsigned long secbase;
1870 const struct kernel_symbol *ksym;
1872 for (i = 1; i < symsec->sh_size / sizeof(Elf_Sym); i++) {
1873 const char *name = info->strtab + sym[i].st_name;
1875 switch (sym[i].st_shndx) {
1877 /* We compiled with -fno-common. These are not
1878 supposed to happen. */
1879 pr_debug("Common symbol: %s\n", name);
1880 printk("%s: please compile with -fno-common\n",
1886 /* Don't need to do anything */
1887 pr_debug("Absolute symbol: 0x%08lx\n",
1888 (long)sym[i].st_value);
1892 ksym = resolve_symbol_wait(mod, info, name);
1893 /* Ok if resolved. */
1894 if (ksym && !IS_ERR(ksym)) {
1895 sym[i].st_value = ksym->value;
1900 if (!ksym && ELF_ST_BIND(sym[i].st_info) == STB_WEAK)
1903 printk(KERN_WARNING "%s: Unknown symbol %s (err %li)\n",
1904 mod->name, name, PTR_ERR(ksym));
1905 ret = PTR_ERR(ksym) ?: -ENOENT;
1909 /* Divert to percpu allocation if a percpu var. */
1910 if (sym[i].st_shndx == info->index.pcpu)
1911 secbase = (unsigned long)mod_percpu(mod);
1913 secbase = info->sechdrs[sym[i].st_shndx].sh_addr;
1914 sym[i].st_value += secbase;
1922 int __weak apply_relocate(Elf_Shdr *sechdrs,
1924 unsigned int symindex,
1925 unsigned int relsec,
1928 pr_err("module %s: REL relocation unsupported\n", me->name);
1932 int __weak apply_relocate_add(Elf_Shdr *sechdrs,
1934 unsigned int symindex,
1935 unsigned int relsec,
1938 pr_err("module %s: RELA relocation unsupported\n", me->name);
1942 static int apply_relocations(struct module *mod, const struct load_info *info)
1947 /* Now do relocations. */
1948 for (i = 1; i < info->hdr->e_shnum; i++) {
1949 unsigned int infosec = info->sechdrs[i].sh_info;
1951 /* Not a valid relocation section? */
1952 if (infosec >= info->hdr->e_shnum)
1955 /* Don't bother with non-allocated sections */
1956 if (!(info->sechdrs[infosec].sh_flags & SHF_ALLOC))
1959 if (info->sechdrs[i].sh_type == SHT_REL)
1960 err = apply_relocate(info->sechdrs, info->strtab,
1961 info->index.sym, i, mod);
1962 else if (info->sechdrs[i].sh_type == SHT_RELA)
1963 err = apply_relocate_add(info->sechdrs, info->strtab,
1964 info->index.sym, i, mod);
1971 /* Additional bytes needed by arch in front of individual sections */
1972 unsigned int __weak arch_mod_section_prepend(struct module *mod,
1973 unsigned int section)
1975 /* default implementation just returns zero */
1979 /* Update size with this section: return offset. */
1980 static long get_offset(struct module *mod, unsigned int *size,
1981 Elf_Shdr *sechdr, unsigned int section)
1985 *size += arch_mod_section_prepend(mod, section);
1986 ret = ALIGN(*size, sechdr->sh_addralign ?: 1);
1987 *size = ret + sechdr->sh_size;
1991 /* Lay out the SHF_ALLOC sections in a way not dissimilar to how ld
1992 might -- code, read-only data, read-write data, small data. Tally
1993 sizes, and place the offsets into sh_entsize fields: high bit means it
1995 static void layout_sections(struct module *mod, struct load_info *info)
1997 static unsigned long const masks[][2] = {
1998 /* NOTE: all executable code must be the first section
1999 * in this array; otherwise modify the text_size
2000 * finder in the two loops below */
2001 { SHF_EXECINSTR | SHF_ALLOC, ARCH_SHF_SMALL },
2002 { SHF_ALLOC, SHF_WRITE | ARCH_SHF_SMALL },
2003 { SHF_WRITE | SHF_ALLOC, ARCH_SHF_SMALL },
2004 { ARCH_SHF_SMALL | SHF_ALLOC, 0 }
2008 for (i = 0; i < info->hdr->e_shnum; i++)
2009 info->sechdrs[i].sh_entsize = ~0UL;
2011 pr_debug("Core section allocation order:\n");
2012 for (m = 0; m < ARRAY_SIZE(masks); ++m) {
2013 for (i = 0; i < info->hdr->e_shnum; ++i) {
2014 Elf_Shdr *s = &info->sechdrs[i];
2015 const char *sname = info->secstrings + s->sh_name;
2017 if ((s->sh_flags & masks[m][0]) != masks[m][0]
2018 || (s->sh_flags & masks[m][1])
2019 || s->sh_entsize != ~0UL
2020 || strstarts(sname, ".init"))
2022 s->sh_entsize = get_offset(mod, &mod->core_size, s, i);
2023 pr_debug("\t%s\n", sname);
2026 case 0: /* executable */
2027 mod->core_size = debug_align(mod->core_size);
2028 mod->core_text_size = mod->core_size;
2030 case 1: /* RO: text and ro-data */
2031 mod->core_size = debug_align(mod->core_size);
2032 mod->core_ro_size = mod->core_size;
2034 case 3: /* whole core */
2035 mod->core_size = debug_align(mod->core_size);
2040 pr_debug("Init section allocation order:\n");
2041 for (m = 0; m < ARRAY_SIZE(masks); ++m) {
2042 for (i = 0; i < info->hdr->e_shnum; ++i) {
2043 Elf_Shdr *s = &info->sechdrs[i];
2044 const char *sname = info->secstrings + s->sh_name;
2046 if ((s->sh_flags & masks[m][0]) != masks[m][0]
2047 || (s->sh_flags & masks[m][1])
2048 || s->sh_entsize != ~0UL
2049 || !strstarts(sname, ".init"))
2051 s->sh_entsize = (get_offset(mod, &mod->init_size, s, i)
2052 | INIT_OFFSET_MASK);
2053 pr_debug("\t%s\n", sname);
2056 case 0: /* executable */
2057 mod->init_size = debug_align(mod->init_size);
2058 mod->init_text_size = mod->init_size;
2060 case 1: /* RO: text and ro-data */
2061 mod->init_size = debug_align(mod->init_size);
2062 mod->init_ro_size = mod->init_size;
2064 case 3: /* whole init */
2065 mod->init_size = debug_align(mod->init_size);
2071 static void set_license(struct module *mod, const char *license)
2074 license = "unspecified";
2076 if (!license_is_gpl_compatible(license)) {
2077 if (!test_taint(TAINT_PROPRIETARY_MODULE))
2078 printk(KERN_WARNING "%s: module license '%s' taints "
2079 "kernel.\n", mod->name, license);
2080 add_taint_module(mod, TAINT_PROPRIETARY_MODULE);
2084 /* Parse tag=value strings from .modinfo section */
2085 static char *next_string(char *string, unsigned long *secsize)
2087 /* Skip non-zero chars */
2090 if ((*secsize)-- <= 1)
2094 /* Skip any zero padding. */
2095 while (!string[0]) {
2097 if ((*secsize)-- <= 1)
2103 static char *get_modinfo(struct load_info *info, const char *tag)
2106 unsigned int taglen = strlen(tag);
2107 Elf_Shdr *infosec = &info->sechdrs[info->index.info];
2108 unsigned long size = infosec->sh_size;
2110 for (p = (char *)infosec->sh_addr; p; p = next_string(p, &size)) {
2111 if (strncmp(p, tag, taglen) == 0 && p[taglen] == '=')
2112 return p + taglen + 1;
2117 static void setup_modinfo(struct module *mod, struct load_info *info)
2119 struct module_attribute *attr;
2122 for (i = 0; (attr = modinfo_attrs[i]); i++) {
2124 attr->setup(mod, get_modinfo(info, attr->attr.name));
2128 static void free_modinfo(struct module *mod)
2130 struct module_attribute *attr;
2133 for (i = 0; (attr = modinfo_attrs[i]); i++) {
2139 #ifdef CONFIG_KALLSYMS
2141 /* lookup symbol in given range of kernel_symbols */
2142 static const struct kernel_symbol *lookup_symbol(const char *name,
2143 const struct kernel_symbol *start,
2144 const struct kernel_symbol *stop)
2146 return bsearch(name, start, stop - start,
2147 sizeof(struct kernel_symbol), cmp_name);
2150 static int is_exported(const char *name, unsigned long value,
2151 const struct module *mod)
2153 const struct kernel_symbol *ks;
2155 ks = lookup_symbol(name, __start___ksymtab, __stop___ksymtab);
2157 ks = lookup_symbol(name, mod->syms, mod->syms + mod->num_syms);
2158 return ks != NULL && ks->value == value;
2162 static char elf_type(const Elf_Sym *sym, const struct load_info *info)
2164 const Elf_Shdr *sechdrs = info->sechdrs;
2166 if (ELF_ST_BIND(sym->st_info) == STB_WEAK) {
2167 if (ELF_ST_TYPE(sym->st_info) == STT_OBJECT)
2172 if (sym->st_shndx == SHN_UNDEF)
2174 if (sym->st_shndx == SHN_ABS)
2176 if (sym->st_shndx >= SHN_LORESERVE)
2178 if (sechdrs[sym->st_shndx].sh_flags & SHF_EXECINSTR)
2180 if (sechdrs[sym->st_shndx].sh_flags & SHF_ALLOC
2181 && sechdrs[sym->st_shndx].sh_type != SHT_NOBITS) {
2182 if (!(sechdrs[sym->st_shndx].sh_flags & SHF_WRITE))
2184 else if (sechdrs[sym->st_shndx].sh_flags & ARCH_SHF_SMALL)
2189 if (sechdrs[sym->st_shndx].sh_type == SHT_NOBITS) {
2190 if (sechdrs[sym->st_shndx].sh_flags & ARCH_SHF_SMALL)
2195 if (strstarts(info->secstrings + sechdrs[sym->st_shndx].sh_name,
2202 static bool is_core_symbol(const Elf_Sym *src, const Elf_Shdr *sechdrs,
2205 const Elf_Shdr *sec;
2207 if (src->st_shndx == SHN_UNDEF
2208 || src->st_shndx >= shnum
2212 sec = sechdrs + src->st_shndx;
2213 if (!(sec->sh_flags & SHF_ALLOC)
2214 #ifndef CONFIG_KALLSYMS_ALL
2215 || !(sec->sh_flags & SHF_EXECINSTR)
2217 || (sec->sh_entsize & INIT_OFFSET_MASK))
2224 * We only allocate and copy the strings needed by the parts of symtab
2225 * we keep. This is simple, but has the effect of making multiple
2226 * copies of duplicates. We could be more sophisticated, see
2227 * linux-kernel thread starting with
2228 * <73defb5e4bca04a6431392cc341112b1@localhost>.
2230 static void layout_symtab(struct module *mod, struct load_info *info)
2232 Elf_Shdr *symsect = info->sechdrs + info->index.sym;
2233 Elf_Shdr *strsect = info->sechdrs + info->index.str;
2235 unsigned int i, nsrc, ndst, strtab_size;
2237 /* Put symbol section at end of init part of module. */
2238 symsect->sh_flags |= SHF_ALLOC;
2239 symsect->sh_entsize = get_offset(mod, &mod->init_size, symsect,
2240 info->index.sym) | INIT_OFFSET_MASK;
2241 pr_debug("\t%s\n", info->secstrings + symsect->sh_name);
2243 src = (void *)info->hdr + symsect->sh_offset;
2244 nsrc = symsect->sh_size / sizeof(*src);
2246 /* Compute total space required for the core symbols' strtab. */
2247 for (ndst = i = strtab_size = 1; i < nsrc; ++i, ++src)
2248 if (is_core_symbol(src, info->sechdrs, info->hdr->e_shnum)) {
2249 strtab_size += strlen(&info->strtab[src->st_name]) + 1;
2253 /* Append room for core symbols at end of core part. */
2254 info->symoffs = ALIGN(mod->core_size, symsect->sh_addralign ?: 1);
2255 info->stroffs = mod->core_size = info->symoffs + ndst * sizeof(Elf_Sym);
2256 mod->core_size += strtab_size;
2258 /* Put string table section at end of init part of module. */
2259 strsect->sh_flags |= SHF_ALLOC;
2260 strsect->sh_entsize = get_offset(mod, &mod->init_size, strsect,
2261 info->index.str) | INIT_OFFSET_MASK;
2262 pr_debug("\t%s\n", info->secstrings + strsect->sh_name);
2265 static void add_kallsyms(struct module *mod, const struct load_info *info)
2267 unsigned int i, ndst;
2271 Elf_Shdr *symsec = &info->sechdrs[info->index.sym];
2273 mod->symtab = (void *)symsec->sh_addr;
2274 mod->num_symtab = symsec->sh_size / sizeof(Elf_Sym);
2275 /* Make sure we get permanent strtab: don't use info->strtab. */
2276 mod->strtab = (void *)info->sechdrs[info->index.str].sh_addr;
2278 /* Set types up while we still have access to sections. */
2279 for (i = 0; i < mod->num_symtab; i++)
2280 mod->symtab[i].st_info = elf_type(&mod->symtab[i], info);
2282 mod->core_symtab = dst = mod->module_core + info->symoffs;
2283 mod->core_strtab = s = mod->module_core + info->stroffs;
2287 for (ndst = i = 1; i < mod->num_symtab; ++i, ++src) {
2288 if (!is_core_symbol(src, info->sechdrs, info->hdr->e_shnum))
2292 dst[ndst++].st_name = s - mod->core_strtab;
2293 s += strlcpy(s, &mod->strtab[src->st_name], KSYM_NAME_LEN) + 1;
2295 mod->core_num_syms = ndst;
2298 static inline void layout_symtab(struct module *mod, struct load_info *info)
2302 static void add_kallsyms(struct module *mod, const struct load_info *info)
2305 #endif /* CONFIG_KALLSYMS */
2307 static void dynamic_debug_setup(struct _ddebug *debug, unsigned int num)
2311 #ifdef CONFIG_DYNAMIC_DEBUG
2312 if (ddebug_add_module(debug, num, debug->modname))
2313 printk(KERN_ERR "dynamic debug error adding module: %s\n",
2318 static void dynamic_debug_remove(struct _ddebug *debug)
2321 ddebug_remove_module(debug->modname);
2324 void * __weak module_alloc(unsigned long size)
2326 return size == 0 ? NULL : vmalloc_exec(size);
2329 static void *module_alloc_update_bounds(unsigned long size)
2331 void *ret = module_alloc(size);
2334 mutex_lock(&module_mutex);
2335 /* Update module bounds. */
2336 if ((unsigned long)ret < module_addr_min)
2337 module_addr_min = (unsigned long)ret;
2338 if ((unsigned long)ret + size > module_addr_max)
2339 module_addr_max = (unsigned long)ret + size;
2340 mutex_unlock(&module_mutex);
2345 #ifdef CONFIG_DEBUG_KMEMLEAK
2346 static void kmemleak_load_module(const struct module *mod,
2347 const struct load_info *info)
2351 /* only scan the sections containing data */
2352 kmemleak_scan_area(mod, sizeof(struct module), GFP_KERNEL);
2354 for (i = 1; i < info->hdr->e_shnum; i++) {
2355 const char *name = info->secstrings + info->sechdrs[i].sh_name;
2356 if (!(info->sechdrs[i].sh_flags & SHF_ALLOC))
2358 if (!strstarts(name, ".data") && !strstarts(name, ".bss"))
2361 kmemleak_scan_area((void *)info->sechdrs[i].sh_addr,
2362 info->sechdrs[i].sh_size, GFP_KERNEL);
2366 static inline void kmemleak_load_module(const struct module *mod,
2367 const struct load_info *info)
2372 /* Sets info->hdr and info->len. */
2373 static int copy_and_check(struct load_info *info,
2374 const void __user *umod, unsigned long len,
2375 const char __user *uargs)
2380 if (len < sizeof(*hdr))
2383 /* Suck in entire file: we'll want most of it. */
2384 /* vmalloc barfs on "unusual" numbers. Check here */
2385 if (len > 64 * 1024 * 1024 || (hdr = vmalloc(len)) == NULL)
2388 if (copy_from_user(hdr, umod, len) != 0) {
2393 /* Sanity checks against insmoding binaries or wrong arch,
2394 weird elf version */
2395 if (memcmp(hdr->e_ident, ELFMAG, SELFMAG) != 0
2396 || hdr->e_type != ET_REL
2397 || !elf_check_arch(hdr)
2398 || hdr->e_shentsize != sizeof(Elf_Shdr)) {
2403 if (len < hdr->e_shoff + hdr->e_shnum * sizeof(Elf_Shdr)) {
2417 static void free_copy(struct load_info *info)
2422 static int rewrite_section_headers(struct load_info *info)
2426 /* This should always be true, but let's be sure. */
2427 info->sechdrs[0].sh_addr = 0;
2429 for (i = 1; i < info->hdr->e_shnum; i++) {
2430 Elf_Shdr *shdr = &info->sechdrs[i];
2431 if (shdr->sh_type != SHT_NOBITS
2432 && info->len < shdr->sh_offset + shdr->sh_size) {
2433 printk(KERN_ERR "Module len %lu truncated\n",
2438 /* Mark all sections sh_addr with their address in the
2440 shdr->sh_addr = (size_t)info->hdr + shdr->sh_offset;
2442 #ifndef CONFIG_MODULE_UNLOAD
2443 /* Don't load .exit sections */
2444 if (strstarts(info->secstrings+shdr->sh_name, ".exit"))
2445 shdr->sh_flags &= ~(unsigned long)SHF_ALLOC;
2449 /* Track but don't keep modinfo and version sections. */
2450 info->index.vers = find_sec(info, "__versions");
2451 info->index.info = find_sec(info, ".modinfo");
2452 info->sechdrs[info->index.info].sh_flags &= ~(unsigned long)SHF_ALLOC;
2453 info->sechdrs[info->index.vers].sh_flags &= ~(unsigned long)SHF_ALLOC;
2458 * Set up our basic convenience variables (pointers to section headers,
2459 * search for module section index etc), and do some basic section
2462 * Return the temporary module pointer (we'll replace it with the final
2463 * one when we move the module sections around).
2465 static struct module *setup_load_info(struct load_info *info)
2471 /* Set up the convenience variables */
2472 info->sechdrs = (void *)info->hdr + info->hdr->e_shoff;
2473 info->secstrings = (void *)info->hdr
2474 + info->sechdrs[info->hdr->e_shstrndx].sh_offset;
2476 err = rewrite_section_headers(info);
2478 return ERR_PTR(err);
2480 /* Find internal symbols and strings. */
2481 for (i = 1; i < info->hdr->e_shnum; i++) {
2482 if (info->sechdrs[i].sh_type == SHT_SYMTAB) {
2483 info->index.sym = i;
2484 info->index.str = info->sechdrs[i].sh_link;
2485 info->strtab = (char *)info->hdr
2486 + info->sechdrs[info->index.str].sh_offset;
2491 info->index.mod = find_sec(info, ".gnu.linkonce.this_module");
2492 if (!info->index.mod) {
2493 printk(KERN_WARNING "No module found in object\n");
2494 return ERR_PTR(-ENOEXEC);
2496 /* This is temporary: point mod into copy of data. */
2497 mod = (void *)info->sechdrs[info->index.mod].sh_addr;
2499 if (info->index.sym == 0) {
2500 printk(KERN_WARNING "%s: module has no symbols (stripped?)\n",
2502 return ERR_PTR(-ENOEXEC);
2505 info->index.pcpu = find_pcpusec(info);
2507 /* Check module struct version now, before we try to use module. */
2508 if (!check_modstruct_version(info->sechdrs, info->index.vers, mod))
2509 return ERR_PTR(-ENOEXEC);
2514 static int check_modinfo(struct module *mod, struct load_info *info)
2516 const char *modmagic = get_modinfo(info, "vermagic");
2519 /* This is allowed: modprobe --force will invalidate it. */
2521 err = try_to_force_load(mod, "bad vermagic");
2524 } else if (!same_magic(modmagic, vermagic, info->index.vers)) {
2525 printk(KERN_ERR "%s: version magic '%s' should be '%s'\n",
2526 mod->name, modmagic, vermagic);
2530 if (!get_modinfo(info, "intree"))
2531 add_taint_module(mod, TAINT_OOT_MODULE);
2533 if (get_modinfo(info, "staging")) {
2534 add_taint_module(mod, TAINT_CRAP);
2535 printk(KERN_WARNING "%s: module is from the staging directory,"
2536 " the quality is unknown, you have been warned.\n",
2540 /* Set up license info based on the info section */
2541 set_license(mod, get_modinfo(info, "license"));
2546 static void find_module_sections(struct module *mod, struct load_info *info)
2548 mod->kp = section_objs(info, "__param",
2549 sizeof(*mod->kp), &mod->num_kp);
2550 mod->syms = section_objs(info, "__ksymtab",
2551 sizeof(*mod->syms), &mod->num_syms);
2552 mod->crcs = section_addr(info, "__kcrctab");
2553 mod->gpl_syms = section_objs(info, "__ksymtab_gpl",
2554 sizeof(*mod->gpl_syms),
2555 &mod->num_gpl_syms);
2556 mod->gpl_crcs = section_addr(info, "__kcrctab_gpl");
2557 mod->gpl_future_syms = section_objs(info,
2558 "__ksymtab_gpl_future",
2559 sizeof(*mod->gpl_future_syms),
2560 &mod->num_gpl_future_syms);
2561 mod->gpl_future_crcs = section_addr(info, "__kcrctab_gpl_future");
2563 #ifdef CONFIG_UNUSED_SYMBOLS
2564 mod->unused_syms = section_objs(info, "__ksymtab_unused",
2565 sizeof(*mod->unused_syms),
2566 &mod->num_unused_syms);
2567 mod->unused_crcs = section_addr(info, "__kcrctab_unused");
2568 mod->unused_gpl_syms = section_objs(info, "__ksymtab_unused_gpl",
2569 sizeof(*mod->unused_gpl_syms),
2570 &mod->num_unused_gpl_syms);
2571 mod->unused_gpl_crcs = section_addr(info, "__kcrctab_unused_gpl");
2573 #ifdef CONFIG_CONSTRUCTORS
2574 mod->ctors = section_objs(info, ".ctors",
2575 sizeof(*mod->ctors), &mod->num_ctors);
2578 #ifdef CONFIG_TRACEPOINTS
2579 mod->tracepoints_ptrs = section_objs(info, "__tracepoints_ptrs",
2580 sizeof(*mod->tracepoints_ptrs),
2581 &mod->num_tracepoints);
2583 #ifdef HAVE_JUMP_LABEL
2584 mod->jump_entries = section_objs(info, "__jump_table",
2585 sizeof(*mod->jump_entries),
2586 &mod->num_jump_entries);
2588 #ifdef CONFIG_EVENT_TRACING
2589 mod->trace_events = section_objs(info, "_ftrace_events",
2590 sizeof(*mod->trace_events),
2591 &mod->num_trace_events);
2593 * This section contains pointers to allocated objects in the trace
2594 * code and not scanning it leads to false positives.
2596 kmemleak_scan_area(mod->trace_events, sizeof(*mod->trace_events) *
2597 mod->num_trace_events, GFP_KERNEL);
2599 #ifdef CONFIG_TRACING
2600 mod->trace_bprintk_fmt_start = section_objs(info, "__trace_printk_fmt",
2601 sizeof(*mod->trace_bprintk_fmt_start),
2602 &mod->num_trace_bprintk_fmt);
2604 * This section contains pointers to allocated objects in the trace
2605 * code and not scanning it leads to false positives.
2607 kmemleak_scan_area(mod->trace_bprintk_fmt_start,
2608 sizeof(*mod->trace_bprintk_fmt_start) *
2609 mod->num_trace_bprintk_fmt, GFP_KERNEL);
2611 #ifdef CONFIG_FTRACE_MCOUNT_RECORD
2612 /* sechdrs[0].sh_size is always zero */
2613 mod->ftrace_callsites = section_objs(info, "__mcount_loc",
2614 sizeof(*mod->ftrace_callsites),
2615 &mod->num_ftrace_callsites);
2618 mod->extable = section_objs(info, "__ex_table",
2619 sizeof(*mod->extable), &mod->num_exentries);
2621 if (section_addr(info, "__obsparm"))
2622 printk(KERN_WARNING "%s: Ignoring obsolete parameters\n",
2625 info->debug = section_objs(info, "__verbose",
2626 sizeof(*info->debug), &info->num_debug);
2629 static int move_module(struct module *mod, struct load_info *info)
2634 /* Do the allocs. */
2635 ptr = module_alloc_update_bounds(mod->core_size);
2637 * The pointer to this block is stored in the module structure
2638 * which is inside the block. Just mark it as not being a
2641 kmemleak_not_leak(ptr);
2645 memset(ptr, 0, mod->core_size);
2646 mod->module_core = ptr;
2648 ptr = module_alloc_update_bounds(mod->init_size);
2650 * The pointer to this block is stored in the module structure
2651 * which is inside the block. This block doesn't need to be
2652 * scanned as it contains data and code that will be freed
2653 * after the module is initialized.
2655 kmemleak_ignore(ptr);
2656 if (!ptr && mod->init_size) {
2657 module_free(mod, mod->module_core);
2660 memset(ptr, 0, mod->init_size);
2661 mod->module_init = ptr;
2663 /* Transfer each section which specifies SHF_ALLOC */
2664 pr_debug("final section addresses:\n");
2665 for (i = 0; i < info->hdr->e_shnum; i++) {
2667 Elf_Shdr *shdr = &info->sechdrs[i];
2669 if (!(shdr->sh_flags & SHF_ALLOC))
2672 if (shdr->sh_entsize & INIT_OFFSET_MASK)
2673 dest = mod->module_init
2674 + (shdr->sh_entsize & ~INIT_OFFSET_MASK);
2676 dest = mod->module_core + shdr->sh_entsize;
2678 if (shdr->sh_type != SHT_NOBITS)
2679 memcpy(dest, (void *)shdr->sh_addr, shdr->sh_size);
2680 /* Update sh_addr to point to copy in image. */
2681 shdr->sh_addr = (unsigned long)dest;
2682 pr_debug("\t0x%lx %s\n",
2683 (long)shdr->sh_addr, info->secstrings + shdr->sh_name);
2689 static int check_module_license_and_versions(struct module *mod)
2692 * ndiswrapper is under GPL by itself, but loads proprietary modules.
2693 * Don't use add_taint_module(), as it would prevent ndiswrapper from
2694 * using GPL-only symbols it needs.
2696 if (strcmp(mod->name, "ndiswrapper") == 0)
2697 add_taint(TAINT_PROPRIETARY_MODULE);
2699 /* driverloader was caught wrongly pretending to be under GPL */
2700 if (strcmp(mod->name, "driverloader") == 0)
2701 add_taint_module(mod, TAINT_PROPRIETARY_MODULE);
2703 #ifdef CONFIG_MODVERSIONS
2704 if ((mod->num_syms && !mod->crcs)
2705 || (mod->num_gpl_syms && !mod->gpl_crcs)
2706 || (mod->num_gpl_future_syms && !mod->gpl_future_crcs)
2707 #ifdef CONFIG_UNUSED_SYMBOLS
2708 || (mod->num_unused_syms && !mod->unused_crcs)
2709 || (mod->num_unused_gpl_syms && !mod->unused_gpl_crcs)
2712 return try_to_force_load(mod,
2713 "no versions for exported symbols");
2719 static void flush_module_icache(const struct module *mod)
2721 mm_segment_t old_fs;
2723 /* flush the icache in correct context */
2728 * Flush the instruction cache, since we've played with text.
2729 * Do it before processing of module parameters, so the module
2730 * can provide parameter accessor functions of its own.
2732 if (mod->module_init)
2733 flush_icache_range((unsigned long)mod->module_init,
2734 (unsigned long)mod->module_init
2736 flush_icache_range((unsigned long)mod->module_core,
2737 (unsigned long)mod->module_core + mod->core_size);
2742 int __weak module_frob_arch_sections(Elf_Ehdr *hdr,
2750 static struct module *layout_and_allocate(struct load_info *info)
2752 /* Module within temporary copy. */
2757 mod = setup_load_info(info);
2761 err = check_modinfo(mod, info);
2763 return ERR_PTR(err);
2765 /* Allow arches to frob section contents and sizes. */
2766 err = module_frob_arch_sections(info->hdr, info->sechdrs,
2767 info->secstrings, mod);
2771 pcpusec = &info->sechdrs[info->index.pcpu];
2772 if (pcpusec->sh_size) {
2773 /* We have a special allocation for this section. */
2774 err = percpu_modalloc(mod,
2775 pcpusec->sh_size, pcpusec->sh_addralign);
2778 pcpusec->sh_flags &= ~(unsigned long)SHF_ALLOC;
2781 /* Determine total sizes, and put offsets in sh_entsize. For now
2782 this is done generically; there doesn't appear to be any
2783 special cases for the architectures. */
2784 layout_sections(mod, info);
2785 layout_symtab(mod, info);
2787 /* Allocate and move to the final place */
2788 err = move_module(mod, info);
2792 /* Module has been copied to its final place now: return it. */
2793 mod = (void *)info->sechdrs[info->index.mod].sh_addr;
2794 kmemleak_load_module(mod, info);
2798 percpu_modfree(mod);
2800 return ERR_PTR(err);
2803 /* mod is no longer valid after this! */
2804 static void module_deallocate(struct module *mod, struct load_info *info)
2806 percpu_modfree(mod);
2807 module_free(mod, mod->module_init);
2808 module_free(mod, mod->module_core);
2811 int __weak module_finalize(const Elf_Ehdr *hdr,
2812 const Elf_Shdr *sechdrs,
2818 static int post_relocation(struct module *mod, const struct load_info *info)
2820 /* Sort exception table now relocations are done. */
2821 sort_extable(mod->extable, mod->extable + mod->num_exentries);
2823 /* Copy relocated percpu area over. */
2824 percpu_modcopy(mod, (void *)info->sechdrs[info->index.pcpu].sh_addr,
2825 info->sechdrs[info->index.pcpu].sh_size);
2827 /* Setup kallsyms-specific fields. */
2828 add_kallsyms(mod, info);
2830 /* Arch-specific module finalizing. */
2831 return module_finalize(info->hdr, info->sechdrs, mod);
2834 /* Allocate and load the module: note that size of section 0 is always
2835 zero, and we rely on this for optional sections. */
2836 static struct module *load_module(void __user *umod,
2838 const char __user *uargs)
2840 struct load_info info = { NULL, };
2844 pr_debug("load_module: umod=%p, len=%lu, uargs=%p\n",
2847 /* Copy in the blobs from userspace, check they are vaguely sane. */
2848 err = copy_and_check(&info, umod, len, uargs);
2850 return ERR_PTR(err);
2852 /* Figure out module layout, and allocate all the memory. */
2853 mod = layout_and_allocate(&info);
2859 /* Now module is in final location, initialize linked lists, etc. */
2860 err = module_unload_init(mod);
2864 /* Now we've got everything in the final locations, we can
2865 * find optional sections. */
2866 find_module_sections(mod, &info);
2868 err = check_module_license_and_versions(mod);
2872 /* Set up MODINFO_ATTR fields */
2873 setup_modinfo(mod, &info);
2875 /* Fix up syms, so that st_value is a pointer to location. */
2876 err = simplify_symbols(mod, &info);
2880 err = apply_relocations(mod, &info);
2884 err = post_relocation(mod, &info);
2888 flush_module_icache(mod);
2890 /* Now copy in args */
2891 mod->args = strndup_user(uargs, ~0UL >> 1);
2892 if (IS_ERR(mod->args)) {
2893 err = PTR_ERR(mod->args);
2894 goto free_arch_cleanup;
2897 /* Mark state as coming so strong_try_module_get() ignores us. */
2898 mod->state = MODULE_STATE_COMING;
2900 /* Now sew it into the lists so we can get lockdep and oops
2901 * info during argument parsing. No one should access us, since
2902 * strong_try_module_get() will fail.
2903 * lockdep/oops can run asynchronous, so use the RCU list insertion
2904 * function to insert in a way safe to concurrent readers.
2905 * The mutex protects against concurrent writers.
2907 mutex_lock(&module_mutex);
2908 if (find_module(mod->name)) {
2913 /* This has to be done once we're sure module name is unique. */
2914 dynamic_debug_setup(info.debug, info.num_debug);
2916 /* Find duplicate symbols */
2917 err = verify_export_symbols(mod);
2921 module_bug_finalize(info.hdr, info.sechdrs, mod);
2922 list_add_rcu(&mod->list, &modules);
2923 mutex_unlock(&module_mutex);
2925 /* Module is ready to execute: parsing args may do that. */
2926 err = parse_args(mod->name, mod->args, mod->kp, mod->num_kp, NULL);
2930 /* Link in to syfs. */
2931 err = mod_sysfs_setup(mod, &info, mod->kp, mod->num_kp);
2935 /* Get rid of temporary copy. */
2939 trace_module_load(mod);
2943 mutex_lock(&module_mutex);
2944 /* Unlink carefully: kallsyms could be walking list. */
2945 list_del_rcu(&mod->list);
2946 module_bug_cleanup(mod);
2949 dynamic_debug_remove(info.debug);
2951 mutex_unlock(&module_mutex);
2952 synchronize_sched();
2955 module_arch_cleanup(mod);
2959 module_unload_free(mod);
2961 module_deallocate(mod, &info);
2964 return ERR_PTR(err);
2967 /* Call module constructors. */
2968 static void do_mod_ctors(struct module *mod)
2970 #ifdef CONFIG_CONSTRUCTORS
2973 for (i = 0; i < mod->num_ctors; i++)
2978 /* This is where the real work happens */
2979 SYSCALL_DEFINE3(init_module, void __user *, umod,
2980 unsigned long, len, const char __user *, uargs)
2985 /* Must have permission */
2986 if (!capable(CAP_SYS_MODULE) || modules_disabled)
2989 /* Do all the hard work */
2990 mod = load_module(umod, len, uargs);
2992 return PTR_ERR(mod);
2994 blocking_notifier_call_chain(&module_notify_list,
2995 MODULE_STATE_COMING, mod);
2997 /* Set RO and NX regions for core */
2998 set_section_ro_nx(mod->module_core,
2999 mod->core_text_size,
3003 /* Set RO and NX regions for init */
3004 set_section_ro_nx(mod->module_init,
3005 mod->init_text_size,
3010 /* Start the module */
3011 if (mod->init != NULL)
3012 ret = do_one_initcall(mod->init);
3014 /* Init routine failed: abort. Try to protect us from
3015 buggy refcounters. */
3016 mod->state = MODULE_STATE_GOING;
3017 synchronize_sched();
3019 blocking_notifier_call_chain(&module_notify_list,
3020 MODULE_STATE_GOING, mod);
3022 wake_up(&module_wq);
3027 "%s: '%s'->init suspiciously returned %d, it should follow 0/-E convention\n"
3028 "%s: loading module anyway...\n",
3029 __func__, mod->name, ret,
3034 /* Now it's a first class citizen! Wake up anyone waiting for it. */
3035 mod->state = MODULE_STATE_LIVE;
3036 wake_up(&module_wq);
3037 blocking_notifier_call_chain(&module_notify_list,
3038 MODULE_STATE_LIVE, mod);
3040 /* We need to finish all async code before the module init sequence is done */
3041 async_synchronize_full();
3043 mutex_lock(&module_mutex);
3044 /* Drop initial reference. */
3046 trim_init_extable(mod);
3047 #ifdef CONFIG_KALLSYMS
3048 mod->num_symtab = mod->core_num_syms;
3049 mod->symtab = mod->core_symtab;
3050 mod->strtab = mod->core_strtab;
3052 unset_module_init_ro_nx(mod);
3053 module_free(mod, mod->module_init);
3054 mod->module_init = NULL;
3056 mod->init_ro_size = 0;
3057 mod->init_text_size = 0;
3058 mutex_unlock(&module_mutex);
3063 static inline int within(unsigned long addr, void *start, unsigned long size)
3065 return ((void *)addr >= start && (void *)addr < start + size);
3068 #ifdef CONFIG_KALLSYMS
3070 * This ignores the intensely annoying "mapping symbols" found
3071 * in ARM ELF files: $a, $t and $d.
3073 static inline int is_arm_mapping_symbol(const char *str)
3075 return str[0] == '$' && strchr("atd", str[1])
3076 && (str[2] == '\0' || str[2] == '.');
3079 static const char *get_ksymbol(struct module *mod,
3081 unsigned long *size,
3082 unsigned long *offset)
3084 unsigned int i, best = 0;
3085 unsigned long nextval;
3087 /* At worse, next value is at end of module */
3088 if (within_module_init(addr, mod))
3089 nextval = (unsigned long)mod->module_init+mod->init_text_size;
3091 nextval = (unsigned long)mod->module_core+mod->core_text_size;
3093 /* Scan for closest preceding symbol, and next symbol. (ELF
3094 starts real symbols at 1). */
3095 for (i = 1; i < mod->num_symtab; i++) {
3096 if (mod->symtab[i].st_shndx == SHN_UNDEF)
3099 /* We ignore unnamed symbols: they're uninformative
3100 * and inserted at a whim. */
3101 if (mod->symtab[i].st_value <= addr
3102 && mod->symtab[i].st_value > mod->symtab[best].st_value
3103 && *(mod->strtab + mod->symtab[i].st_name) != '\0'
3104 && !is_arm_mapping_symbol(mod->strtab + mod->symtab[i].st_name))
3106 if (mod->symtab[i].st_value > addr
3107 && mod->symtab[i].st_value < nextval
3108 && *(mod->strtab + mod->symtab[i].st_name) != '\0'
3109 && !is_arm_mapping_symbol(mod->strtab + mod->symtab[i].st_name))
3110 nextval = mod->symtab[i].st_value;
3117 *size = nextval - mod->symtab[best].st_value;
3119 *offset = addr - mod->symtab[best].st_value;
3120 return mod->strtab + mod->symtab[best].st_name;
3123 /* For kallsyms to ask for address resolution. NULL means not found. Careful
3124 * not to lock to avoid deadlock on oopses, simply disable preemption. */
3125 const char *module_address_lookup(unsigned long addr,
3126 unsigned long *size,
3127 unsigned long *offset,
3132 const char *ret = NULL;
3135 list_for_each_entry_rcu(mod, &modules, list) {
3136 if (within_module_init(addr, mod) ||
3137 within_module_core(addr, mod)) {
3139 *modname = mod->name;
3140 ret = get_ksymbol(mod, addr, size, offset);
3144 /* Make a copy in here where it's safe */
3146 strncpy(namebuf, ret, KSYM_NAME_LEN - 1);
3153 int lookup_module_symbol_name(unsigned long addr, char *symname)
3158 list_for_each_entry_rcu(mod, &modules, list) {
3159 if (within_module_init(addr, mod) ||
3160 within_module_core(addr, mod)) {
3163 sym = get_ksymbol(mod, addr, NULL, NULL);
3166 strlcpy(symname, sym, KSYM_NAME_LEN);
3176 int lookup_module_symbol_attrs(unsigned long addr, unsigned long *size,
3177 unsigned long *offset, char *modname, char *name)
3182 list_for_each_entry_rcu(mod, &modules, list) {
3183 if (within_module_init(addr, mod) ||
3184 within_module_core(addr, mod)) {
3187 sym = get_ksymbol(mod, addr, size, offset);
3191 strlcpy(modname, mod->name, MODULE_NAME_LEN);
3193 strlcpy(name, sym, KSYM_NAME_LEN);
3203 int module_get_kallsym(unsigned int symnum, unsigned long *value, char *type,
3204 char *name, char *module_name, int *exported)
3209 list_for_each_entry_rcu(mod, &modules, list) {
3210 if (symnum < mod->num_symtab) {
3211 *value = mod->symtab[symnum].st_value;
3212 *type = mod->symtab[symnum].st_info;
3213 strlcpy(name, mod->strtab + mod->symtab[symnum].st_name,
3215 strlcpy(module_name, mod->name, MODULE_NAME_LEN);
3216 *exported = is_exported(name, *value, mod);
3220 symnum -= mod->num_symtab;
3226 static unsigned long mod_find_symname(struct module *mod, const char *name)
3230 for (i = 0; i < mod->num_symtab; i++)
3231 if (strcmp(name, mod->strtab+mod->symtab[i].st_name) == 0 &&
3232 mod->symtab[i].st_info != 'U')
3233 return mod->symtab[i].st_value;
3237 /* Look for this name: can be of form module:name. */
3238 unsigned long module_kallsyms_lookup_name(const char *name)
3242 unsigned long ret = 0;
3244 /* Don't lock: we're in enough trouble already. */
3246 if ((colon = strchr(name, ':')) != NULL) {
3248 if ((mod = find_module(name)) != NULL)
3249 ret = mod_find_symname(mod, colon+1);
3252 list_for_each_entry_rcu(mod, &modules, list)
3253 if ((ret = mod_find_symname(mod, name)) != 0)
3260 int module_kallsyms_on_each_symbol(int (*fn)(void *, const char *,
3261 struct module *, unsigned long),
3268 list_for_each_entry(mod, &modules, list) {
3269 for (i = 0; i < mod->num_symtab; i++) {
3270 ret = fn(data, mod->strtab + mod->symtab[i].st_name,
3271 mod, mod->symtab[i].st_value);
3278 #endif /* CONFIG_KALLSYMS */
3280 static char *module_flags(struct module *mod, char *buf)
3285 mod->state == MODULE_STATE_GOING ||
3286 mod->state == MODULE_STATE_COMING) {
3288 bx += module_flags_taint(mod, buf + bx);
3289 /* Show a - for module-is-being-unloaded */
3290 if (mod->state == MODULE_STATE_GOING)
3292 /* Show a + for module-is-being-loaded */
3293 if (mod->state == MODULE_STATE_COMING)
3302 #ifdef CONFIG_PROC_FS
3303 /* Called by the /proc file system to return a list of modules. */
3304 static void *m_start(struct seq_file *m, loff_t *pos)
3306 mutex_lock(&module_mutex);
3307 return seq_list_start(&modules, *pos);
3310 static void *m_next(struct seq_file *m, void *p, loff_t *pos)
3312 return seq_list_next(p, &modules, pos);
3315 static void m_stop(struct seq_file *m, void *p)
3317 mutex_unlock(&module_mutex);
3320 static int m_show(struct seq_file *m, void *p)
3322 struct module *mod = list_entry(p, struct module, list);
3325 seq_printf(m, "%s %u",
3326 mod->name, mod->init_size + mod->core_size);
3327 print_unload_info(m, mod);
3329 /* Informative for users. */
3330 seq_printf(m, " %s",
3331 mod->state == MODULE_STATE_GOING ? "Unloading":
3332 mod->state == MODULE_STATE_COMING ? "Loading":
3334 /* Used by oprofile and other similar tools. */
3335 seq_printf(m, " 0x%pK", mod->module_core);
3339 seq_printf(m, " %s", module_flags(mod, buf));
3341 seq_printf(m, "\n");
3345 /* Format: modulename size refcount deps address
3347 Where refcount is a number or -, and deps is a comma-separated list
3350 static const struct seq_operations modules_op = {
3357 static int modules_open(struct inode *inode, struct file *file)
3359 return seq_open(file, &modules_op);
3362 static const struct file_operations proc_modules_operations = {
3363 .open = modules_open,
3365 .llseek = seq_lseek,
3366 .release = seq_release,
3369 static int __init proc_modules_init(void)
3371 proc_create("modules", 0, NULL, &proc_modules_operations);
3374 module_init(proc_modules_init);
3377 /* Given an address, look for it in the module exception tables. */
3378 const struct exception_table_entry *search_module_extables(unsigned long addr)
3380 const struct exception_table_entry *e = NULL;
3384 list_for_each_entry_rcu(mod, &modules, list) {
3385 if (mod->num_exentries == 0)
3388 e = search_extable(mod->extable,
3389 mod->extable + mod->num_exentries - 1,
3396 /* Now, if we found one, we are running inside it now, hence
3397 we cannot unload the module, hence no refcnt needed. */
3402 * is_module_address - is this address inside a module?
3403 * @addr: the address to check.
3405 * See is_module_text_address() if you simply want to see if the address
3406 * is code (not data).
3408 bool is_module_address(unsigned long addr)
3413 ret = __module_address(addr) != NULL;
3420 * __module_address - get the module which contains an address.
3421 * @addr: the address.
3423 * Must be called with preempt disabled or module mutex held so that
3424 * module doesn't get freed during this.
3426 struct module *__module_address(unsigned long addr)
3430 if (addr < module_addr_min || addr > module_addr_max)
3433 list_for_each_entry_rcu(mod, &modules, list)
3434 if (within_module_core(addr, mod)
3435 || within_module_init(addr, mod))
3439 EXPORT_SYMBOL_GPL(__module_address);
3442 * is_module_text_address - is this address inside module code?
3443 * @addr: the address to check.
3445 * See is_module_address() if you simply want to see if the address is
3446 * anywhere in a module. See kernel_text_address() for testing if an
3447 * address corresponds to kernel or module code.
3449 bool is_module_text_address(unsigned long addr)
3454 ret = __module_text_address(addr) != NULL;
3461 * __module_text_address - get the module whose code contains an address.
3462 * @addr: the address.
3464 * Must be called with preempt disabled or module mutex held so that
3465 * module doesn't get freed during this.
3467 struct module *__module_text_address(unsigned long addr)
3469 struct module *mod = __module_address(addr);
3471 /* Make sure it's within the text section. */
3472 if (!within(addr, mod->module_init, mod->init_text_size)
3473 && !within(addr, mod->module_core, mod->core_text_size))
3478 EXPORT_SYMBOL_GPL(__module_text_address);
3480 /* Don't grab lock, we're oopsing. */
3481 void print_modules(void)
3486 printk(KERN_DEFAULT "Modules linked in:");
3487 /* Most callers should already have preempt disabled, but make sure */
3489 list_for_each_entry_rcu(mod, &modules, list)
3490 printk(" %s%s", mod->name, module_flags(mod, buf));
3492 if (last_unloaded_module[0])
3493 printk(" [last unloaded: %s]", last_unloaded_module);
3497 #ifdef CONFIG_MODVERSIONS
3498 /* Generate the signature for all relevant module structures here.
3499 * If these change, we don't want to try to parse the module. */
3500 void module_layout(struct module *mod,
3501 struct modversion_info *ver,
3502 struct kernel_param *kp,
3503 struct kernel_symbol *ks,
3504 struct tracepoint * const *tp)
3507 EXPORT_SYMBOL(module_layout);