linux/kernel/module.c
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   1/*
   2   Copyright (C) 2002 Richard Henderson
   3   Copyright (C) 2001 Rusty Russell, 2002 Rusty Russell IBM.
   4
   5    This program is free software; you can redistribute it and/or modify
   6    it under the terms of the GNU General Public License as published by
   7    the Free Software Foundation; either version 2 of the License, or
   8    (at your option) any later version.
   9
  10    This program is distributed in the hope that it will be useful,
  11    but WITHOUT ANY WARRANTY; without even the implied warranty of
  12    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13    GNU General Public License for more details.
  14
  15    You should have received a copy of the GNU General Public License
  16    along with this program; if not, write to the Free Software
  17    Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  18*/
  19#include <linux/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
  59#define CREATE_TRACE_POINTS
  60#include <trace/events/module.h>
  61
  62EXPORT_TRACEPOINT_SYMBOL(module_get);
  63
  64#if 0
  65#define DEBUGP printk
  66#else
  67#define DEBUGP(fmt , a...)
  68#endif
  69
  70#ifndef ARCH_SHF_SMALL
  71#define ARCH_SHF_SMALL 0
  72#endif
  73
  74/* If this is set, the section belongs in the init part of the module */
  75#define INIT_OFFSET_MASK (1UL << (BITS_PER_LONG-1))
  76
  77/* List of modules, protected by module_mutex or preempt_disable
  78 * (delete uses stop_machine/add uses RCU list operations). */
  79DEFINE_MUTEX(module_mutex);
  80EXPORT_SYMBOL_GPL(module_mutex);
  81static LIST_HEAD(modules);
  82
  83/* Block module loading/unloading? */
  84int modules_disabled = 0;
  85
  86/* Waiting for a module to finish initializing? */
  87static DECLARE_WAIT_QUEUE_HEAD(module_wq);
  88
  89static BLOCKING_NOTIFIER_HEAD(module_notify_list);
  90
  91/* Bounds of module allocation, for speeding __module_address */
  92static unsigned long module_addr_min = -1UL, module_addr_max = 0;
  93
  94int register_module_notifier(struct notifier_block * nb)
  95{
  96        return blocking_notifier_chain_register(&module_notify_list, nb);
  97}
  98EXPORT_SYMBOL(register_module_notifier);
  99
 100int unregister_module_notifier(struct notifier_block * nb)
 101{
 102        return blocking_notifier_chain_unregister(&module_notify_list, nb);
 103}
 104EXPORT_SYMBOL(unregister_module_notifier);
 105
 106/* We require a truly strong try_module_get(): 0 means failure due to
 107   ongoing or failed initialization etc. */
 108static inline int strong_try_module_get(struct module *mod)
 109{
 110        if (mod && mod->state == MODULE_STATE_COMING)
 111                return -EBUSY;
 112        if (try_module_get(mod))
 113                return 0;
 114        else
 115                return -ENOENT;
 116}
 117
 118static inline void add_taint_module(struct module *mod, unsigned flag)
 119{
 120        add_taint(flag);
 121        mod->taints |= (1U << flag);
 122}
 123
 124/*
 125 * A thread that wants to hold a reference to a module only while it
 126 * is running can call this to safely exit.  nfsd and lockd use this.
 127 */
 128void __module_put_and_exit(struct module *mod, long code)
 129{
 130        module_put(mod);
 131        do_exit(code);
 132}
 133EXPORT_SYMBOL(__module_put_and_exit);
 134
 135/* Find a module section: 0 means not found. */
 136static unsigned int find_sec(Elf_Ehdr *hdr,
 137                             Elf_Shdr *sechdrs,
 138                             const char *secstrings,
 139                             const char *name)
 140{
 141        unsigned int i;
 142
 143        for (i = 1; i < hdr->e_shnum; i++)
 144                /* Alloc bit cleared means "ignore it." */
 145                if ((sechdrs[i].sh_flags & SHF_ALLOC)
 146                    && strcmp(secstrings+sechdrs[i].sh_name, name) == 0)
 147                        return i;
 148        return 0;
 149}
 150
 151/* Find a module section, or NULL. */
 152static void *section_addr(Elf_Ehdr *hdr, Elf_Shdr *shdrs,
 153                          const char *secstrings, const char *name)
 154{
 155        /* Section 0 has sh_addr 0. */
 156        return (void *)shdrs[find_sec(hdr, shdrs, secstrings, name)].sh_addr;
 157}
 158
 159/* Find a module section, or NULL.  Fill in number of "objects" in section. */
 160static void *section_objs(Elf_Ehdr *hdr,
 161                          Elf_Shdr *sechdrs,
 162                          const char *secstrings,
 163                          const char *name,
 164                          size_t object_size,
 165                          unsigned int *num)
 166{
 167        unsigned int sec = find_sec(hdr, sechdrs, secstrings, name);
 168
 169        /* Section 0 has sh_addr 0 and sh_size 0. */
 170        *num = sechdrs[sec].sh_size / object_size;
 171        return (void *)sechdrs[sec].sh_addr;
 172}
 173
 174/* Provided by the linker */
 175extern const struct kernel_symbol __start___ksymtab[];
 176extern const struct kernel_symbol __stop___ksymtab[];
 177extern const struct kernel_symbol __start___ksymtab_gpl[];
 178extern const struct kernel_symbol __stop___ksymtab_gpl[];
 179extern const struct kernel_symbol __start___ksymtab_gpl_future[];
 180extern const struct kernel_symbol __stop___ksymtab_gpl_future[];
 181extern const struct kernel_symbol __start___ksymtab_gpl_future[];
 182extern const struct kernel_symbol __stop___ksymtab_gpl_future[];
 183extern const unsigned long __start___kcrctab[];
 184extern const unsigned long __start___kcrctab_gpl[];
 185extern const unsigned long __start___kcrctab_gpl_future[];
 186#ifdef CONFIG_UNUSED_SYMBOLS
 187extern const struct kernel_symbol __start___ksymtab_unused[];
 188extern const struct kernel_symbol __stop___ksymtab_unused[];
 189extern const struct kernel_symbol __start___ksymtab_unused_gpl[];
 190extern const struct kernel_symbol __stop___ksymtab_unused_gpl[];
 191extern const unsigned long __start___kcrctab_unused[];
 192extern const unsigned long __start___kcrctab_unused_gpl[];
 193#endif
 194
 195#ifndef CONFIG_MODVERSIONS
 196#define symversion(base, idx) NULL
 197#else
 198#define symversion(base, idx) ((base != NULL) ? ((base) + (idx)) : NULL)
 199#endif
 200
 201static bool each_symbol_in_section(const struct symsearch *arr,
 202                                   unsigned int arrsize,
 203                                   struct module *owner,
 204                                   bool (*fn)(const struct symsearch *syms,
 205                                              struct module *owner,
 206                                              unsigned int symnum, void *data),
 207                                   void *data)
 208{
 209        unsigned int i, j;
 210
 211        for (j = 0; j < arrsize; j++) {
 212                for (i = 0; i < arr[j].stop - arr[j].start; i++)
 213                        if (fn(&arr[j], owner, i, data))
 214                                return true;
 215        }
 216
 217        return false;
 218}
 219
 220/* Returns true as soon as fn returns true, otherwise false. */
 221bool each_symbol(bool (*fn)(const struct symsearch *arr, struct module *owner,
 222                            unsigned int symnum, void *data), void *data)
 223{
 224        struct module *mod;
 225        const struct symsearch arr[] = {
 226                { __start___ksymtab, __stop___ksymtab, __start___kcrctab,
 227                  NOT_GPL_ONLY, false },
 228                { __start___ksymtab_gpl, __stop___ksymtab_gpl,
 229                  __start___kcrctab_gpl,
 230                  GPL_ONLY, false },
 231                { __start___ksymtab_gpl_future, __stop___ksymtab_gpl_future,
 232                  __start___kcrctab_gpl_future,
 233                  WILL_BE_GPL_ONLY, false },
 234#ifdef CONFIG_UNUSED_SYMBOLS
 235                { __start___ksymtab_unused, __stop___ksymtab_unused,
 236                  __start___kcrctab_unused,
 237                  NOT_GPL_ONLY, true },
 238                { __start___ksymtab_unused_gpl, __stop___ksymtab_unused_gpl,
 239                  __start___kcrctab_unused_gpl,
 240                  GPL_ONLY, true },
 241#endif
 242        };
 243
 244        if (each_symbol_in_section(arr, ARRAY_SIZE(arr), NULL, fn, data))
 245                return true;
 246
 247        list_for_each_entry_rcu(mod, &modules, list) {
 248                struct symsearch arr[] = {
 249                        { mod->syms, mod->syms + mod->num_syms, mod->crcs,
 250                          NOT_GPL_ONLY, false },
 251                        { mod->gpl_syms, mod->gpl_syms + mod->num_gpl_syms,
 252                          mod->gpl_crcs,
 253                          GPL_ONLY, false },
 254                        { mod->gpl_future_syms,
 255                          mod->gpl_future_syms + mod->num_gpl_future_syms,
 256                          mod->gpl_future_crcs,
 257                          WILL_BE_GPL_ONLY, false },
 258#ifdef CONFIG_UNUSED_SYMBOLS
 259                        { mod->unused_syms,
 260                          mod->unused_syms + mod->num_unused_syms,
 261                          mod->unused_crcs,
 262                          NOT_GPL_ONLY, true },
 263                        { mod->unused_gpl_syms,
 264                          mod->unused_gpl_syms + mod->num_unused_gpl_syms,
 265                          mod->unused_gpl_crcs,
 266                          GPL_ONLY, true },
 267#endif
 268                };
 269
 270                if (each_symbol_in_section(arr, ARRAY_SIZE(arr), mod, fn, data))
 271                        return true;
 272        }
 273        return false;
 274}
 275EXPORT_SYMBOL_GPL(each_symbol);
 276
 277struct find_symbol_arg {
 278        /* Input */
 279        const char *name;
 280        bool gplok;
 281        bool warn;
 282
 283        /* Output */
 284        struct module *owner;
 285        const unsigned long *crc;
 286        const struct kernel_symbol *sym;
 287};
 288
 289static bool find_symbol_in_section(const struct symsearch *syms,
 290                                   struct module *owner,
 291                                   unsigned int symnum, void *data)
 292{
 293        struct find_symbol_arg *fsa = data;
 294
 295        if (strcmp(syms->start[symnum].name, fsa->name) != 0)
 296                return false;
 297
 298        if (!fsa->gplok) {
 299                if (syms->licence == GPL_ONLY)
 300                        return false;
 301                if (syms->licence == WILL_BE_GPL_ONLY && fsa->warn) {
 302                        printk(KERN_WARNING "Symbol %s is being used "
 303                               "by a non-GPL module, which will not "
 304                               "be allowed in the future\n", fsa->name);
 305                        printk(KERN_WARNING "Please see the file "
 306                               "Documentation/feature-removal-schedule.txt "
 307                               "in the kernel source tree for more details.\n");
 308                }
 309        }
 310
 311#ifdef CONFIG_UNUSED_SYMBOLS
 312        if (syms->unused && fsa->warn) {
 313                printk(KERN_WARNING "Symbol %s is marked as UNUSED, "
 314                       "however this module is using it.\n", fsa->name);
 315                printk(KERN_WARNING
 316                       "This symbol will go away in the future.\n");
 317                printk(KERN_WARNING
 318                       "Please evalute if this is the right api to use and if "
 319                       "it really is, submit a report the linux kernel "
 320                       "mailinglist together with submitting your code for "
 321                       "inclusion.\n");
 322        }
 323#endif
 324
 325        fsa->owner = owner;
 326        fsa->crc = symversion(syms->crcs, symnum);
 327        fsa->sym = &syms->start[symnum];
 328        return true;
 329}
 330
 331/* Find a symbol and return it, along with, (optional) crc and
 332 * (optional) module which owns it */
 333const struct kernel_symbol *find_symbol(const char *name,
 334                                        struct module **owner,
 335                                        const unsigned long **crc,
 336                                        bool gplok,
 337                                        bool warn)
 338{
 339        struct find_symbol_arg fsa;
 340
 341        fsa.name = name;
 342        fsa.gplok = gplok;
 343        fsa.warn = warn;
 344
 345        if (each_symbol(find_symbol_in_section, &fsa)) {
 346                if (owner)
 347                        *owner = fsa.owner;
 348                if (crc)
 349                        *crc = fsa.crc;
 350                return fsa.sym;
 351        }
 352
 353        DEBUGP("Failed to find symbol %s\n", name);
 354        return NULL;
 355}
 356EXPORT_SYMBOL_GPL(find_symbol);
 357
 358/* Search for module by name: must hold module_mutex. */
 359struct module *find_module(const char *name)
 360{
 361        struct module *mod;
 362
 363        list_for_each_entry(mod, &modules, list) {
 364                if (strcmp(mod->name, name) == 0)
 365                        return mod;
 366        }
 367        return NULL;
 368}
 369EXPORT_SYMBOL_GPL(find_module);
 370
 371#ifdef CONFIG_SMP
 372
 373#ifndef CONFIG_HAVE_LEGACY_PER_CPU_AREA
 374
 375static void *percpu_modalloc(unsigned long size, unsigned long align,
 376                             const char *name)
 377{
 378        void *ptr;
 379
 380        if (align > PAGE_SIZE) {
 381                printk(KERN_WARNING "%s: per-cpu alignment %li > %li\n",
 382                       name, align, PAGE_SIZE);
 383                align = PAGE_SIZE;
 384        }
 385
 386        ptr = __alloc_reserved_percpu(size, align);
 387        if (!ptr)
 388                printk(KERN_WARNING
 389                       "Could not allocate %lu bytes percpu data\n", size);
 390        return ptr;
 391}
 392
 393static void percpu_modfree(void *freeme)
 394{
 395        free_percpu(freeme);
 396}
 397
 398#else /* ... CONFIG_HAVE_LEGACY_PER_CPU_AREA */
 399
 400/* Number of blocks used and allocated. */
 401static unsigned int pcpu_num_used, pcpu_num_allocated;
 402/* Size of each block.  -ve means used. */
 403static int *pcpu_size;
 404
 405static int split_block(unsigned int i, unsigned short size)
 406{
 407        /* Reallocation required? */
 408        if (pcpu_num_used + 1 > pcpu_num_allocated) {
 409                int *new;
 410
 411                new = krealloc(pcpu_size, sizeof(new[0])*pcpu_num_allocated*2,
 412                               GFP_KERNEL);
 413                if (!new)
 414                        return 0;
 415
 416                pcpu_num_allocated *= 2;
 417                pcpu_size = new;
 418        }
 419
 420        /* Insert a new subblock */
 421        memmove(&pcpu_size[i+1], &pcpu_size[i],
 422                sizeof(pcpu_size[0]) * (pcpu_num_used - i));
 423        pcpu_num_used++;
 424
 425        pcpu_size[i+1] -= size;
 426        pcpu_size[i] = size;
 427        return 1;
 428}
 429
 430static inline unsigned int block_size(int val)
 431{
 432        if (val < 0)
 433                return -val;
 434        return val;
 435}
 436
 437static void *percpu_modalloc(unsigned long size, unsigned long align,
 438                             const char *name)
 439{
 440        unsigned long extra;
 441        unsigned int i;
 442        void *ptr;
 443        int cpu;
 444
 445        if (align > PAGE_SIZE) {
 446                printk(KERN_WARNING "%s: per-cpu alignment %li > %li\n",
 447                       name, align, PAGE_SIZE);
 448                align = PAGE_SIZE;
 449        }
 450
 451        ptr = __per_cpu_start;
 452        for (i = 0; i < pcpu_num_used; ptr += block_size(pcpu_size[i]), i++) {
 453                /* Extra for alignment requirement. */
 454                extra = ALIGN((unsigned long)ptr, align) - (unsigned long)ptr;
 455                BUG_ON(i == 0 && extra != 0);
 456
 457                if (pcpu_size[i] < 0 || pcpu_size[i] < extra + size)
 458                        continue;
 459
 460                /* Transfer extra to previous block. */
 461                if (pcpu_size[i-1] < 0)
 462                        pcpu_size[i-1] -= extra;
 463                else
 464                        pcpu_size[i-1] += extra;
 465                pcpu_size[i] -= extra;
 466                ptr += extra;
 467
 468                /* Split block if warranted */
 469                if (pcpu_size[i] - size > sizeof(unsigned long))
 470                        if (!split_block(i, size))
 471                                return NULL;
 472
 473                /* add the per-cpu scanning areas */
 474                for_each_possible_cpu(cpu)
 475                        kmemleak_alloc(ptr + per_cpu_offset(cpu), size, 0,
 476                                       GFP_KERNEL);
 477
 478                /* Mark allocated */
 479                pcpu_size[i] = -pcpu_size[i];
 480                return ptr;
 481        }
 482
 483        printk(KERN_WARNING "Could not allocate %lu bytes percpu data\n",
 484               size);
 485        return NULL;
 486}
 487
 488static void percpu_modfree(void *freeme)
 489{
 490        unsigned int i;
 491        void *ptr = __per_cpu_start + block_size(pcpu_size[0]);
 492        int cpu;
 493
 494        /* First entry is core kernel percpu data. */
 495        for (i = 1; i < pcpu_num_used; ptr += block_size(pcpu_size[i]), i++) {
 496                if (ptr == freeme) {
 497                        pcpu_size[i] = -pcpu_size[i];
 498                        goto free;
 499                }
 500        }
 501        BUG();
 502
 503 free:
 504        /* remove the per-cpu scanning areas */
 505        for_each_possible_cpu(cpu)
 506                kmemleak_free(freeme + per_cpu_offset(cpu));
 507
 508        /* Merge with previous? */
 509        if (pcpu_size[i-1] >= 0) {
 510                pcpu_size[i-1] += pcpu_size[i];
 511                pcpu_num_used--;
 512                memmove(&pcpu_size[i], &pcpu_size[i+1],
 513                        (pcpu_num_used - i) * sizeof(pcpu_size[0]));
 514                i--;
 515        }
 516        /* Merge with next? */
 517        if (i+1 < pcpu_num_used && pcpu_size[i+1] >= 0) {
 518                pcpu_size[i] += pcpu_size[i+1];
 519                pcpu_num_used--;
 520                memmove(&pcpu_size[i+1], &pcpu_size[i+2],
 521                        (pcpu_num_used - (i+1)) * sizeof(pcpu_size[0]));
 522        }
 523}
 524
 525static int percpu_modinit(void)
 526{
 527        pcpu_num_used = 2;
 528        pcpu_num_allocated = 2;
 529        pcpu_size = kmalloc(sizeof(pcpu_size[0]) * pcpu_num_allocated,
 530                            GFP_KERNEL);
 531        /* Static in-kernel percpu data (used). */
 532        pcpu_size[0] = -(__per_cpu_end-__per_cpu_start);
 533        /* Free room. */
 534        pcpu_size[1] = PERCPU_ENOUGH_ROOM + pcpu_size[0];
 535        if (pcpu_size[1] < 0) {
 536                printk(KERN_ERR "No per-cpu room for modules.\n");
 537                pcpu_num_used = 1;
 538        }
 539
 540        return 0;
 541}
 542__initcall(percpu_modinit);
 543
 544#endif /* CONFIG_HAVE_LEGACY_PER_CPU_AREA */
 545
 546static unsigned int find_pcpusec(Elf_Ehdr *hdr,
 547                                 Elf_Shdr *sechdrs,
 548                                 const char *secstrings)
 549{
 550        return find_sec(hdr, sechdrs, secstrings, ".data.percpu");
 551}
 552
 553static void percpu_modcopy(void *pcpudest, const void *from, unsigned long size)
 554{
 555        int cpu;
 556
 557        for_each_possible_cpu(cpu)
 558                memcpy(pcpudest + per_cpu_offset(cpu), from, size);
 559}
 560
 561#else /* ... !CONFIG_SMP */
 562
 563static inline void *percpu_modalloc(unsigned long size, unsigned long align,
 564                                    const char *name)
 565{
 566        return NULL;
 567}
 568static inline void percpu_modfree(void *pcpuptr)
 569{
 570        BUG();
 571}
 572static inline unsigned int find_pcpusec(Elf_Ehdr *hdr,
 573                                        Elf_Shdr *sechdrs,
 574                                        const char *secstrings)
 575{
 576        return 0;
 577}
 578static inline void percpu_modcopy(void *pcpudst, const void *src,
 579                                  unsigned long size)
 580{
 581        /* pcpusec should be 0, and size of that section should be 0. */
 582        BUG_ON(size != 0);
 583}
 584
 585#endif /* CONFIG_SMP */
 586
 587#define MODINFO_ATTR(field)     \
 588static void setup_modinfo_##field(struct module *mod, const char *s)  \
 589{                                                                     \
 590        mod->field = kstrdup(s, GFP_KERNEL);                          \
 591}                                                                     \
 592static ssize_t show_modinfo_##field(struct module_attribute *mattr,   \
 593                        struct module *mod, char *buffer)             \
 594{                                                                     \
 595        return sprintf(buffer, "%s\n", mod->field);                   \
 596}                                                                     \
 597static int modinfo_##field##_exists(struct module *mod)               \
 598{                                                                     \
 599        return mod->field != NULL;                                    \
 600}                                                                     \
 601static void free_modinfo_##field(struct module *mod)                  \
 602{                                                                     \
 603        kfree(mod->field);                                            \
 604        mod->field = NULL;                                            \
 605}                                                                     \
 606static struct module_attribute modinfo_##field = {                    \
 607        .attr = { .name = __stringify(field), .mode = 0444 },         \
 608        .show = show_modinfo_##field,                                 \
 609        .setup = setup_modinfo_##field,                               \
 610        .test = modinfo_##field##_exists,                             \
 611        .free = free_modinfo_##field,                                 \
 612};
 613
 614MODINFO_ATTR(version);
 615MODINFO_ATTR(srcversion);
 616
 617static char last_unloaded_module[MODULE_NAME_LEN+1];
 618
 619#ifdef CONFIG_MODULE_UNLOAD
 620/* Init the unload section of the module. */
 621static void module_unload_init(struct module *mod)
 622{
 623        int cpu;
 624
 625        INIT_LIST_HEAD(&mod->modules_which_use_me);
 626        for_each_possible_cpu(cpu)
 627                local_set(__module_ref_addr(mod, cpu), 0);
 628        /* Hold reference count during initialization. */
 629        local_set(__module_ref_addr(mod, raw_smp_processor_id()), 1);
 630        /* Backwards compatibility macros put refcount during init. */
 631        mod->waiter = current;
 632}
 633
 634/* modules using other modules */
 635struct module_use
 636{
 637        struct list_head list;
 638        struct module *module_which_uses;
 639};
 640
 641/* Does a already use b? */
 642static int already_uses(struct module *a, struct module *b)
 643{
 644        struct module_use *use;
 645
 646        list_for_each_entry(use, &b->modules_which_use_me, list) {
 647                if (use->module_which_uses == a) {
 648                        DEBUGP("%s uses %s!\n", a->name, b->name);
 649                        return 1;
 650                }
 651        }
 652        DEBUGP("%s does not use %s!\n", a->name, b->name);
 653        return 0;
 654}
 655
 656/* Module a uses b */
 657int use_module(struct module *a, struct module *b)
 658{
 659        struct module_use *use;
 660        int no_warn, err;
 661
 662        if (b == NULL || already_uses(a, b)) return 1;
 663
 664        /* If we're interrupted or time out, we fail. */
 665        if (wait_event_interruptible_timeout(
 666                    module_wq, (err = strong_try_module_get(b)) != -EBUSY,
 667                    30 * HZ) <= 0) {
 668                printk("%s: gave up waiting for init of module %s.\n",
 669                       a->name, b->name);
 670                return 0;
 671        }
 672
 673        /* If strong_try_module_get() returned a different error, we fail. */
 674        if (err)
 675                return 0;
 676
 677        DEBUGP("Allocating new usage for %s.\n", a->name);
 678        use = kmalloc(sizeof(*use), GFP_ATOMIC);
 679        if (!use) {
 680                printk("%s: out of memory loading\n", a->name);
 681                module_put(b);
 682                return 0;
 683        }
 684
 685        use->module_which_uses = a;
 686        list_add(&use->list, &b->modules_which_use_me);
 687        no_warn = sysfs_create_link(b->holders_dir, &a->mkobj.kobj, a->name);
 688        return 1;
 689}
 690EXPORT_SYMBOL_GPL(use_module);
 691
 692/* Clear the unload stuff of the module. */
 693static void module_unload_free(struct module *mod)
 694{
 695        struct module *i;
 696
 697        list_for_each_entry(i, &modules, list) {
 698                struct module_use *use;
 699
 700                list_for_each_entry(use, &i->modules_which_use_me, list) {
 701                        if (use->module_which_uses == mod) {
 702                                DEBUGP("%s unusing %s\n", mod->name, i->name);
 703                                module_put(i);
 704                                list_del(&use->list);
 705                                kfree(use);
 706                                sysfs_remove_link(i->holders_dir, mod->name);
 707                                /* There can be at most one match. */
 708                                break;
 709                        }
 710                }
 711        }
 712}
 713
 714#ifdef CONFIG_MODULE_FORCE_UNLOAD
 715static inline int try_force_unload(unsigned int flags)
 716{
 717        int ret = (flags & O_TRUNC);
 718        if (ret)
 719                add_taint(TAINT_FORCED_RMMOD);
 720        return ret;
 721}
 722#else
 723static inline int try_force_unload(unsigned int flags)
 724{
 725        return 0;
 726}
 727#endif /* CONFIG_MODULE_FORCE_UNLOAD */
 728
 729struct stopref
 730{
 731        struct module *mod;
 732        int flags;
 733        int *forced;
 734};
 735
 736/* Whole machine is stopped with interrupts off when this runs. */
 737static int __try_stop_module(void *_sref)
 738{
 739        struct stopref *sref = _sref;
 740
 741        /* If it's not unused, quit unless we're forcing. */
 742        if (module_refcount(sref->mod) != 0) {
 743                if (!(*sref->forced = try_force_unload(sref->flags)))
 744                        return -EWOULDBLOCK;
 745        }
 746
 747        /* Mark it as dying. */
 748        sref->mod->state = MODULE_STATE_GOING;
 749        return 0;
 750}
 751
 752static int try_stop_module(struct module *mod, int flags, int *forced)
 753{
 754        if (flags & O_NONBLOCK) {
 755                struct stopref sref = { mod, flags, forced };
 756
 757                return stop_machine(__try_stop_module, &sref, NULL);
 758        } else {
 759                /* We don't need to stop the machine for this. */
 760                mod->state = MODULE_STATE_GOING;
 761                synchronize_sched();
 762                return 0;
 763        }
 764}
 765
 766unsigned int module_refcount(struct module *mod)
 767{
 768        unsigned int total = 0;
 769        int cpu;
 770
 771        for_each_possible_cpu(cpu)
 772                total += local_read(__module_ref_addr(mod, cpu));
 773        return total;
 774}
 775EXPORT_SYMBOL(module_refcount);
 776
 777/* This exists whether we can unload or not */
 778static void free_module(struct module *mod);
 779
 780static void wait_for_zero_refcount(struct module *mod)
 781{
 782        /* Since we might sleep for some time, release the mutex first */
 783        mutex_unlock(&module_mutex);
 784        for (;;) {
 785                DEBUGP("Looking at refcount...\n");
 786                set_current_state(TASK_UNINTERRUPTIBLE);
 787                if (module_refcount(mod) == 0)
 788                        break;
 789                schedule();
 790        }
 791        current->state = TASK_RUNNING;
 792        mutex_lock(&module_mutex);
 793}
 794
 795SYSCALL_DEFINE2(delete_module, const char __user *, name_user,
 796                unsigned int, flags)
 797{
 798        struct module *mod;
 799        char name[MODULE_NAME_LEN];
 800        int ret, forced = 0;
 801
 802        if (!capable(CAP_SYS_MODULE) || modules_disabled)
 803                return -EPERM;
 804
 805        if (strncpy_from_user(name, name_user, MODULE_NAME_LEN-1) < 0)
 806                return -EFAULT;
 807        name[MODULE_NAME_LEN-1] = '\0';
 808
 809        /* Create stop_machine threads since free_module relies on
 810         * a non-failing stop_machine call. */
 811        ret = stop_machine_create();
 812        if (ret)
 813                return ret;
 814
 815        if (mutex_lock_interruptible(&module_mutex) != 0) {
 816                ret = -EINTR;
 817                goto out_stop;
 818        }
 819
 820        mod = find_module(name);
 821        if (!mod) {
 822                ret = -ENOENT;
 823                goto out;
 824        }
 825
 826        if (!list_empty(&mod->modules_which_use_me)) {
 827                /* Other modules depend on us: get rid of them first. */
 828                ret = -EWOULDBLOCK;
 829                goto out;
 830        }
 831
 832        /* Doing init or already dying? */
 833        if (mod->state != MODULE_STATE_LIVE) {
 834                /* FIXME: if (force), slam module count and wake up
 835                   waiter --RR */
 836                DEBUGP("%s already dying\n", mod->name);
 837                ret = -EBUSY;
 838                goto out;
 839        }
 840
 841        /* If it has an init func, it must have an exit func to unload */
 842        if (mod->init && !mod->exit) {
 843                forced = try_force_unload(flags);
 844                if (!forced) {
 845                        /* This module can't be removed */
 846                        ret = -EBUSY;
 847                        goto out;
 848                }
 849        }
 850
 851        /* Set this up before setting mod->state */
 852        mod->waiter = current;
 853
 854        /* Stop the machine so refcounts can't move and disable module. */
 855        ret = try_stop_module(mod, flags, &forced);
 856        if (ret != 0)
 857                goto out;
 858
 859        /* Never wait if forced. */
 860        if (!forced && module_refcount(mod) != 0)
 861                wait_for_zero_refcount(mod);
 862
 863        mutex_unlock(&module_mutex);
 864        /* Final destruction now noone is using it. */
 865        if (mod->exit != NULL)
 866                mod->exit();
 867        blocking_notifier_call_chain(&module_notify_list,
 868                                     MODULE_STATE_GOING, mod);
 869        async_synchronize_full();
 870        mutex_lock(&module_mutex);
 871        /* Store the name of the last unloaded module for diagnostic purposes */
 872        strlcpy(last_unloaded_module, mod->name, sizeof(last_unloaded_module));
 873        ddebug_remove_module(mod->name);
 874        free_module(mod);
 875
 876 out:
 877        mutex_unlock(&module_mutex);
 878out_stop:
 879        stop_machine_destroy();
 880        return ret;
 881}
 882
 883static inline void print_unload_info(struct seq_file *m, struct module *mod)
 884{
 885        struct module_use *use;
 886        int printed_something = 0;
 887
 888        seq_printf(m, " %u ", module_refcount(mod));
 889
 890        /* Always include a trailing , so userspace can differentiate
 891           between this and the old multi-field proc format. */
 892        list_for_each_entry(use, &mod->modules_which_use_me, list) {
 893                printed_something = 1;
 894                seq_printf(m, "%s,", use->module_which_uses->name);
 895        }
 896
 897        if (mod->init != NULL && mod->exit == NULL) {
 898                printed_something = 1;
 899                seq_printf(m, "[permanent],");
 900        }
 901
 902        if (!printed_something)
 903                seq_printf(m, "-");
 904}
 905
 906void __symbol_put(const char *symbol)
 907{
 908        struct module *owner;
 909
 910        preempt_disable();
 911        if (!find_symbol(symbol, &owner, NULL, true, false))
 912                BUG();
 913        module_put(owner);
 914        preempt_enable();
 915}
 916EXPORT_SYMBOL(__symbol_put);
 917
 918/* Note this assumes addr is a function, which it currently always is. */
 919void symbol_put_addr(void *addr)
 920{
 921        struct module *modaddr;
 922        unsigned long a = (unsigned long)dereference_function_descriptor(addr);
 923
 924        if (core_kernel_text(a))
 925                return;
 926
 927        /* module_text_address is safe here: we're supposed to have reference
 928         * to module from symbol_get, so it can't go away. */
 929        modaddr = __module_text_address(a);
 930        BUG_ON(!modaddr);
 931        module_put(modaddr);
 932}
 933EXPORT_SYMBOL_GPL(symbol_put_addr);
 934
 935static ssize_t show_refcnt(struct module_attribute *mattr,
 936                           struct module *mod, char *buffer)
 937{
 938        return sprintf(buffer, "%u\n", module_refcount(mod));
 939}
 940
 941static struct module_attribute refcnt = {
 942        .attr = { .name = "refcnt", .mode = 0444 },
 943        .show = show_refcnt,
 944};
 945
 946void module_put(struct module *module)
 947{
 948        if (module) {
 949                unsigned int cpu = get_cpu();
 950                local_dec(__module_ref_addr(module, cpu));
 951                trace_module_put(module, _RET_IP_,
 952                                 local_read(__module_ref_addr(module, cpu)));
 953                /* Maybe they're waiting for us to drop reference? */
 954                if (unlikely(!module_is_live(module)))
 955                        wake_up_process(module->waiter);
 956                put_cpu();
 957        }
 958}
 959EXPORT_SYMBOL(module_put);
 960
 961#else /* !CONFIG_MODULE_UNLOAD */
 962static inline void print_unload_info(struct seq_file *m, struct module *mod)
 963{
 964        /* We don't know the usage count, or what modules are using. */
 965        seq_printf(m, " - -");
 966}
 967
 968static inline void module_unload_free(struct module *mod)
 969{
 970}
 971
 972int use_module(struct module *a, struct module *b)
 973{
 974        return strong_try_module_get(b) == 0;
 975}
 976EXPORT_SYMBOL_GPL(use_module);
 977
 978static inline void module_unload_init(struct module *mod)
 979{
 980}
 981#endif /* CONFIG_MODULE_UNLOAD */
 982
 983static ssize_t show_initstate(struct module_attribute *mattr,
 984                           struct module *mod, char *buffer)
 985{
 986        const char *state = "unknown";
 987
 988        switch (mod->state) {
 989        case MODULE_STATE_LIVE:
 990                state = "live";
 991                break;
 992        case MODULE_STATE_COMING:
 993                state = "coming";
 994                break;
 995        case MODULE_STATE_GOING:
 996                state = "going";
 997                break;
 998        }
 999        return sprintf(buffer, "%s\n", state);
1000}
1001
1002static struct module_attribute initstate = {
1003        .attr = { .name = "initstate", .mode = 0444 },
1004        .show = show_initstate,
1005};
1006
1007static struct module_attribute *modinfo_attrs[] = {
1008        &modinfo_version,
1009        &modinfo_srcversion,
1010        &initstate,
1011#ifdef CONFIG_MODULE_UNLOAD
1012        &refcnt,
1013#endif
1014        NULL,
1015};
1016
1017static const char vermagic[] = VERMAGIC_STRING;
1018
1019static int try_to_force_load(struct module *mod, const char *reason)
1020{
1021#ifdef CONFIG_MODULE_FORCE_LOAD
1022        if (!test_taint(TAINT_FORCED_MODULE))
1023                printk(KERN_WARNING "%s: %s: kernel tainted.\n",
1024                       mod->name, reason);
1025        add_taint_module(mod, TAINT_FORCED_MODULE);
1026        return 0;
1027#else
1028        return -ENOEXEC;
1029#endif
1030}
1031
1032#ifdef CONFIG_MODVERSIONS
1033static int check_version(Elf_Shdr *sechdrs,
1034                         unsigned int versindex,
1035                         const char *symname,
1036                         struct module *mod, 
1037                         const unsigned long *crc)
1038{
1039        unsigned int i, num_versions;
1040        struct modversion_info *versions;
1041
1042        /* Exporting module didn't supply crcs?  OK, we're already tainted. */
1043        if (!crc)
1044                return 1;
1045
1046        /* No versions at all?  modprobe --force does this. */
1047        if (versindex == 0)
1048                return try_to_force_load(mod, symname) == 0;
1049
1050        versions = (void *) sechdrs[versindex].sh_addr;
1051        num_versions = sechdrs[versindex].sh_size
1052                / sizeof(struct modversion_info);
1053
1054        for (i = 0; i < num_versions; i++) {
1055                if (strcmp(versions[i].name, symname) != 0)
1056                        continue;
1057
1058                if (versions[i].crc == *crc)
1059                        return 1;
1060                DEBUGP("Found checksum %lX vs module %lX\n",
1061                       *crc, versions[i].crc);
1062                goto bad_version;
1063        }
1064
1065        printk(KERN_WARNING "%s: no symbol version for %s\n",
1066               mod->name, symname);
1067        return 0;
1068
1069bad_version:
1070        printk("%s: disagrees about version of symbol %s\n",
1071               mod->name, symname);
1072        return 0;
1073}
1074
1075static inline int check_modstruct_version(Elf_Shdr *sechdrs,
1076                                          unsigned int versindex,
1077                                          struct module *mod)
1078{
1079        const unsigned long *crc;
1080
1081        if (!find_symbol(MODULE_SYMBOL_PREFIX "module_layout", NULL,
1082                         &crc, true, false))
1083                BUG();
1084        return check_version(sechdrs, versindex, "module_layout", mod, crc);
1085}
1086
1087/* First part is kernel version, which we ignore if module has crcs. */
1088static inline int same_magic(const char *amagic, const char *bmagic,
1089                             bool has_crcs)
1090{
1091        if (has_crcs) {
1092                amagic += strcspn(amagic, " ");
1093                bmagic += strcspn(bmagic, " ");
1094        }
1095        return strcmp(amagic, bmagic) == 0;
1096}
1097#else
1098static inline int check_version(Elf_Shdr *sechdrs,
1099                                unsigned int versindex,
1100                                const char *symname,
1101                                struct module *mod, 
1102                                const unsigned long *crc)
1103{
1104        return 1;
1105}
1106
1107static inline int check_modstruct_version(Elf_Shdr *sechdrs,
1108                                          unsigned int versindex,
1109                                          struct module *mod)
1110{
1111        return 1;
1112}
1113
1114static inline int same_magic(const char *amagic, const char *bmagic,
1115                             bool has_crcs)
1116{
1117        return strcmp(amagic, bmagic) == 0;
1118}
1119#endif /* CONFIG_MODVERSIONS */
1120
1121/* Resolve a symbol for this module.  I.e. if we find one, record usage.
1122   Must be holding module_mutex. */
1123static const struct kernel_symbol *resolve_symbol(Elf_Shdr *sechdrs,
1124                                                  unsigned int versindex,
1125                                                  const char *name,
1126                                                  struct module *mod)
1127{
1128        struct module *owner;
1129        const struct kernel_symbol *sym;
1130        const unsigned long *crc;
1131
1132        sym = find_symbol(name, &owner, &crc,
1133                          !(mod->taints & (1 << TAINT_PROPRIETARY_MODULE)), true);
1134        /* use_module can fail due to OOM,
1135           or module initialization or unloading */
1136        if (sym) {
1137                if (!check_version(sechdrs, versindex, name, mod, crc) ||
1138                    !use_module(mod, owner))
1139                        sym = NULL;
1140        }
1141        return sym;
1142}
1143
1144/*
1145 * /sys/module/foo/sections stuff
1146 * J. Corbet <corbet@lwn.net>
1147 */
1148#if defined(CONFIG_KALLSYMS) && defined(CONFIG_SYSFS)
1149struct module_sect_attr
1150{
1151        struct module_attribute mattr;
1152        char *name;
1153        unsigned long address;
1154};
1155
1156struct module_sect_attrs
1157{
1158        struct attribute_group grp;
1159        unsigned int nsections;
1160        struct module_sect_attr attrs[0];
1161};
1162
1163static ssize_t module_sect_show(struct module_attribute *mattr,
1164                                struct module *mod, char *buf)
1165{
1166        struct module_sect_attr *sattr =
1167                container_of(mattr, struct module_sect_attr, mattr);
1168        return sprintf(buf, "0x%lx\n", sattr->address);
1169}
1170
1171static void free_sect_attrs(struct module_sect_attrs *sect_attrs)
1172{
1173        unsigned int section;
1174
1175        for (section = 0; section < sect_attrs->nsections; section++)
1176                kfree(sect_attrs->attrs[section].name);
1177        kfree(sect_attrs);
1178}
1179
1180static void add_sect_attrs(struct module *mod, unsigned int nsect,
1181                char *secstrings, Elf_Shdr *sechdrs)
1182{
1183        unsigned int nloaded = 0, i, size[2];
1184        struct module_sect_attrs *sect_attrs;
1185        struct module_sect_attr *sattr;
1186        struct attribute **gattr;
1187
1188        /* Count loaded sections and allocate structures */
1189        for (i = 0; i < nsect; i++)
1190                if (sechdrs[i].sh_flags & SHF_ALLOC
1191                    && sechdrs[i].sh_size)
1192                        nloaded++;
1193        size[0] = ALIGN(sizeof(*sect_attrs)
1194                        + nloaded * sizeof(sect_attrs->attrs[0]),
1195                        sizeof(sect_attrs->grp.attrs[0]));
1196        size[1] = (nloaded + 1) * sizeof(sect_attrs->grp.attrs[0]);
1197        sect_attrs = kzalloc(size[0] + size[1], GFP_KERNEL);
1198        if (sect_attrs == NULL)
1199                return;
1200
1201        /* Setup section attributes. */
1202        sect_attrs->grp.name = "sections";
1203        sect_attrs->grp.attrs = (void *)sect_attrs + size[0];
1204
1205        sect_attrs->nsections = 0;
1206        sattr = &sect_attrs->attrs[0];
1207        gattr = &sect_attrs->grp.attrs[0];
1208        for (i = 0; i < nsect; i++) {
1209                if (! (sechdrs[i].sh_flags & SHF_ALLOC))
1210                        continue;
1211                if (!sechdrs[i].sh_size)
1212                        continue;
1213                sattr->address = sechdrs[i].sh_addr;
1214                sattr->name = kstrdup(secstrings + sechdrs[i].sh_name,
1215                                        GFP_KERNEL);
1216                if (sattr->name == NULL)
1217                        goto out;
1218                sect_attrs->nsections++;
1219                sattr->mattr.show = module_sect_show;
1220                sattr->mattr.store = NULL;
1221                sattr->mattr.attr.name = sattr->name;
1222                sattr->mattr.attr.mode = S_IRUGO;
1223                *(gattr++) = &(sattr++)->mattr.attr;
1224        }
1225        *gattr = NULL;
1226
1227        if (sysfs_create_group(&mod->mkobj.kobj, &sect_attrs->grp))
1228                goto out;
1229
1230        mod->sect_attrs = sect_attrs;
1231        return;
1232  out:
1233        free_sect_attrs(sect_attrs);
1234}
1235
1236static void remove_sect_attrs(struct module *mod)
1237{
1238        if (mod->sect_attrs) {
1239                sysfs_remove_group(&mod->mkobj.kobj,
1240                                   &mod->sect_attrs->grp);
1241                /* We are positive that no one is using any sect attrs
1242                 * at this point.  Deallocate immediately. */
1243                free_sect_attrs(mod->sect_attrs);
1244                mod->sect_attrs = NULL;
1245        }
1246}
1247
1248/*
1249 * /sys/module/foo/notes/.section.name gives contents of SHT_NOTE sections.
1250 */
1251
1252struct module_notes_attrs {
1253        struct kobject *dir;
1254        unsigned int notes;
1255        struct bin_attribute attrs[0];
1256};
1257
1258static ssize_t module_notes_read(struct kobject *kobj,
1259                                 struct bin_attribute *bin_attr,
1260                                 char *buf, loff_t pos, size_t count)
1261{
1262        /*
1263         * The caller checked the pos and count against our size.
1264         */
1265        memcpy(buf, bin_attr->private + pos, count);
1266        return count;
1267}
1268
1269static void free_notes_attrs(struct module_notes_attrs *notes_attrs,
1270                             unsigned int i)
1271{
1272        if (notes_attrs->dir) {
1273                while (i-- > 0)
1274                        sysfs_remove_bin_file(notes_attrs->dir,
1275                                              &notes_attrs->attrs[i]);
1276                kobject_put(notes_attrs->dir);
1277        }
1278        kfree(notes_attrs);
1279}
1280
1281static void add_notes_attrs(struct module *mod, unsigned int nsect,
1282                            char *secstrings, Elf_Shdr *sechdrs)
1283{
1284        unsigned int notes, loaded, i;
1285        struct module_notes_attrs *notes_attrs;
1286        struct bin_attribute *nattr;
1287
1288        /* failed to create section attributes, so can't create notes */
1289        if (!mod->sect_attrs)
1290                return;
1291
1292        /* Count notes sections and allocate structures.  */
1293        notes = 0;
1294        for (i = 0; i < nsect; i++)
1295                if ((sechdrs[i].sh_flags & SHF_ALLOC) &&
1296                    (sechdrs[i].sh_type == SHT_NOTE))
1297                        ++notes;
1298
1299        if (notes == 0)
1300                return;
1301
1302        notes_attrs = kzalloc(sizeof(*notes_attrs)
1303                              + notes * sizeof(notes_attrs->attrs[0]),
1304                              GFP_KERNEL);
1305        if (notes_attrs == NULL)
1306                return;
1307
1308        notes_attrs->notes = notes;
1309        nattr = &notes_attrs->attrs[0];
1310        for (loaded = i = 0; i < nsect; ++i) {
1311                if (!(sechdrs[i].sh_flags & SHF_ALLOC))
1312                        continue;
1313                if (sechdrs[i].sh_type == SHT_NOTE) {
1314                        nattr->attr.name = mod->sect_attrs->attrs[loaded].name;
1315                        nattr->attr.mode = S_IRUGO;
1316                        nattr->size = sechdrs[i].sh_size;
1317                        nattr->private = (void *) sechdrs[i].sh_addr;
1318                        nattr->read = module_notes_read;
1319                        ++nattr;
1320                }
1321                ++loaded;
1322        }
1323
1324        notes_attrs->dir = kobject_create_and_add("notes", &mod->mkobj.kobj);
1325        if (!notes_attrs->dir)
1326                goto out;
1327
1328        for (i = 0; i < notes; ++i)
1329                if (sysfs_create_bin_file(notes_attrs->dir,
1330                                          &notes_attrs->attrs[i]))
1331                        goto out;
1332
1333        mod->notes_attrs = notes_attrs;
1334        return;
1335
1336  out:
1337        free_notes_attrs(notes_attrs, i);
1338}
1339
1340static void remove_notes_attrs(struct module *mod)
1341{
1342        if (mod->notes_attrs)
1343                free_notes_attrs(mod->notes_attrs, mod->notes_attrs->notes);
1344}
1345
1346#else
1347
1348static inline void add_sect_attrs(struct module *mod, unsigned int nsect,
1349                char *sectstrings, Elf_Shdr *sechdrs)
1350{
1351}
1352
1353static inline void remove_sect_attrs(struct module *mod)
1354{
1355}
1356
1357static inline void add_notes_attrs(struct module *mod, unsigned int nsect,
1358                                   char *sectstrings, Elf_Shdr *sechdrs)
1359{
1360}
1361
1362static inline void remove_notes_attrs(struct module *mod)
1363{
1364}
1365#endif
1366
1367#ifdef CONFIG_SYSFS
1368int module_add_modinfo_attrs(struct module *mod)
1369{
1370        struct module_attribute *attr;
1371        struct module_attribute *temp_attr;
1372        int error = 0;
1373        int i;
1374
1375        mod->modinfo_attrs = kzalloc((sizeof(struct module_attribute) *
1376                                        (ARRAY_SIZE(modinfo_attrs) + 1)),
1377                                        GFP_KERNEL);
1378        if (!mod->modinfo_attrs)
1379                return -ENOMEM;
1380
1381        temp_attr = mod->modinfo_attrs;
1382        for (i = 0; (attr = modinfo_attrs[i]) && !error; i++) {
1383                if (!attr->test ||
1384                    (attr->test && attr->test(mod))) {
1385                        memcpy(temp_attr, attr, sizeof(*temp_attr));
1386                        error = sysfs_create_file(&mod->mkobj.kobj,&temp_attr->attr);
1387                        ++temp_attr;
1388                }
1389        }
1390        return error;
1391}
1392
1393void module_remove_modinfo_attrs(struct module *mod)
1394{
1395        struct module_attribute *attr;
1396        int i;
1397
1398        for (i = 0; (attr = &mod->modinfo_attrs[i]); i++) {
1399                /* pick a field to test for end of list */
1400                if (!attr->attr.name)
1401                        break;
1402                sysfs_remove_file(&mod->mkobj.kobj,&attr->attr);
1403                if (attr->free)
1404                        attr->free(mod);
1405        }
1406        kfree(mod->modinfo_attrs);
1407}
1408
1409int mod_sysfs_init(struct module *mod)
1410{
1411        int err;
1412        struct kobject *kobj;
1413
1414        if (!module_sysfs_initialized) {
1415                printk(KERN_ERR "%s: module sysfs not initialized\n",
1416                       mod->name);
1417                err = -EINVAL;
1418                goto out;
1419        }
1420
1421        kobj = kset_find_obj(module_kset, mod->name);
1422        if (kobj) {
1423                printk(KERN_ERR "%s: module is already loaded\n", mod->name);
1424                kobject_put(kobj);
1425                err = -EINVAL;
1426                goto out;
1427        }
1428
1429        mod->mkobj.mod = mod;
1430
1431        memset(&mod->mkobj.kobj, 0, sizeof(mod->mkobj.kobj));
1432        mod->mkobj.kobj.kset = module_kset;
1433        err = kobject_init_and_add(&mod->mkobj.kobj, &module_ktype, NULL,
1434                                   "%s", mod->name);
1435        if (err)
1436                kobject_put(&mod->mkobj.kobj);
1437
1438        /* delay uevent until full sysfs population */
1439out:
1440        return err;
1441}
1442
1443int mod_sysfs_setup(struct module *mod,
1444                           struct kernel_param *kparam,
1445                           unsigned int num_params)
1446{
1447        int err;
1448
1449        mod->holders_dir = kobject_create_and_add("holders", &mod->mkobj.kobj);
1450        if (!mod->holders_dir) {
1451                err = -ENOMEM;
1452                goto out_unreg;
1453        }
1454
1455        err = module_param_sysfs_setup(mod, kparam, num_params);
1456        if (err)
1457                goto out_unreg_holders;
1458
1459        err = module_add_modinfo_attrs(mod);
1460        if (err)
1461                goto out_unreg_param;
1462
1463        kobject_uevent(&mod->mkobj.kobj, KOBJ_ADD);
1464        return 0;
1465
1466out_unreg_param:
1467        module_param_sysfs_remove(mod);
1468out_unreg_holders:
1469        kobject_put(mod->holders_dir);
1470out_unreg:
1471        kobject_put(&mod->mkobj.kobj);
1472        return err;
1473}
1474
1475static void mod_sysfs_fini(struct module *mod)
1476{
1477        kobject_put(&mod->mkobj.kobj);
1478}
1479
1480#else /* CONFIG_SYSFS */
1481
1482static void mod_sysfs_fini(struct module *mod)
1483{
1484}
1485
1486#endif /* CONFIG_SYSFS */
1487
1488static void mod_kobject_remove(struct module *mod)
1489{
1490        module_remove_modinfo_attrs(mod);
1491        module_param_sysfs_remove(mod);
1492        kobject_put(mod->mkobj.drivers_dir);
1493        kobject_put(mod->holders_dir);
1494        mod_sysfs_fini(mod);
1495}
1496
1497/*
1498 * unlink the module with the whole machine is stopped with interrupts off
1499 * - this defends against kallsyms not taking locks
1500 */
1501static int __unlink_module(void *_mod)
1502{
1503        struct module *mod = _mod;
1504        list_del(&mod->list);
1505        return 0;
1506}
1507
1508/* Free a module, remove from lists, etc (must hold module_mutex). */
1509static void free_module(struct module *mod)
1510{
1511        trace_module_free(mod);
1512
1513        /* Delete from various lists */
1514        stop_machine(__unlink_module, mod, NULL);
1515        remove_notes_attrs(mod);
1516        remove_sect_attrs(mod);
1517        mod_kobject_remove(mod);
1518
1519        /* Arch-specific cleanup. */
1520        module_arch_cleanup(mod);
1521
1522        /* Module unload stuff */
1523        module_unload_free(mod);
1524
1525        /* Free any allocated parameters. */
1526        destroy_params(mod->kp, mod->num_kp);
1527
1528        /* This may be NULL, but that's OK */
1529        module_free(mod, mod->module_init);
1530        kfree(mod->args);
1531        if (mod->percpu)
1532                percpu_modfree(mod->percpu);
1533#if defined(CONFIG_MODULE_UNLOAD) && defined(CONFIG_SMP)
1534        if (mod->refptr)
1535                percpu_modfree(mod->refptr);
1536#endif
1537        /* Free lock-classes: */
1538        lockdep_free_key_range(mod->module_core, mod->core_size);
1539
1540        /* Finally, free the core (containing the module structure) */
1541        module_free(mod, mod->module_core);
1542
1543#ifdef CONFIG_MPU
1544        update_protections(current->mm);
1545#endif
1546}
1547
1548void *__symbol_get(const char *symbol)
1549{
1550        struct module *owner;
1551        const struct kernel_symbol *sym;
1552
1553        preempt_disable();
1554        sym = find_symbol(symbol, &owner, NULL, true, true);
1555        if (sym && strong_try_module_get(owner))
1556                sym = NULL;
1557        preempt_enable();
1558
1559        return sym ? (void *)sym->value : NULL;
1560}
1561EXPORT_SYMBOL_GPL(__symbol_get);
1562
1563/*
1564 * Ensure that an exported symbol [global namespace] does not already exist
1565 * in the kernel or in some other module's exported symbol table.
1566 */
1567static int verify_export_symbols(struct module *mod)
1568{
1569        unsigned int i;
1570        struct module *owner;
1571        const struct kernel_symbol *s;
1572        struct {
1573                const struct kernel_symbol *sym;
1574                unsigned int num;
1575        } arr[] = {
1576                { mod->syms, mod->num_syms },
1577                { mod->gpl_syms, mod->num_gpl_syms },
1578                { mod->gpl_future_syms, mod->num_gpl_future_syms },
1579#ifdef CONFIG_UNUSED_SYMBOLS
1580                { mod->unused_syms, mod->num_unused_syms },
1581                { mod->unused_gpl_syms, mod->num_unused_gpl_syms },
1582#endif
1583        };
1584
1585        for (i = 0; i < ARRAY_SIZE(arr); i++) {
1586                for (s = arr[i].sym; s < arr[i].sym + arr[i].num; s++) {
1587                        if (find_symbol(s->name, &owner, NULL, true, false)) {
1588                                printk(KERN_ERR
1589                                       "%s: exports duplicate symbol %s"
1590                                       " (owned by %s)\n",
1591                                       mod->name, s->name, module_name(owner));
1592                                return -ENOEXEC;
1593                        }
1594                }
1595        }
1596        return 0;
1597}
1598
1599/* Change all symbols so that st_value encodes the pointer directly. */
1600static int simplify_symbols(Elf_Shdr *sechdrs,
1601                            unsigned int symindex,
1602                            const char *strtab,
1603                            unsigned int versindex,
1604                            unsigned int pcpuindex,
1605                            struct module *mod)
1606{
1607        Elf_Sym *sym = (void *)sechdrs[symindex].sh_addr;
1608        unsigned long secbase;
1609        unsigned int i, n = sechdrs[symindex].sh_size / sizeof(Elf_Sym);
1610        int ret = 0;
1611        const struct kernel_symbol *ksym;
1612
1613        for (i = 1; i < n; i++) {
1614                switch (sym[i].st_shndx) {
1615                case SHN_COMMON:
1616                        /* We compiled with -fno-common.  These are not
1617                           supposed to happen.  */
1618                        DEBUGP("Common symbol: %s\n", strtab + sym[i].st_name);
1619                        printk("%s: please compile with -fno-common\n",
1620                               mod->name);
1621                        ret = -ENOEXEC;
1622                        break;
1623
1624                case SHN_ABS:
1625                        /* Don't need to do anything */
1626                        DEBUGP("Absolute symbol: 0x%08lx\n",
1627                               (long)sym[i].st_value);
1628                        break;
1629
1630                case SHN_UNDEF:
1631                        ksym = resolve_symbol(sechdrs, versindex,
1632                                              strtab + sym[i].st_name, mod);
1633                        /* Ok if resolved.  */
1634                        if (ksym) {
1635                                sym[i].st_value = ksym->value;
1636                                break;
1637                        }
1638
1639                        /* Ok if weak.  */
1640                        if (ELF_ST_BIND(sym[i].st_info) == STB_WEAK)
1641                                break;
1642
1643                        printk(KERN_WARNING "%s: Unknown symbol %s\n",
1644                               mod->name, strtab + sym[i].st_name);
1645                        ret = -ENOENT;
1646                        break;
1647
1648                default:
1649                        /* Divert to percpu allocation if a percpu var. */
1650                        if (sym[i].st_shndx == pcpuindex)
1651                                secbase = (unsigned long)mod->percpu;
1652                        else
1653                                secbase = sechdrs[sym[i].st_shndx].sh_addr;
1654                        sym[i].st_value += secbase;
1655                        break;
1656                }
1657        }
1658
1659        return ret;
1660}
1661
1662/* Additional bytes needed by arch in front of individual sections */
1663unsigned int __weak arch_mod_section_prepend(struct module *mod,
1664                                             unsigned int section)
1665{
1666        /* default implementation just returns zero */
1667        return 0;
1668}
1669
1670/* Update size with this section: return offset. */
1671static long get_offset(struct module *mod, unsigned int *size,
1672                       Elf_Shdr *sechdr, unsigned int section)
1673{
1674        long ret;
1675
1676        *size += arch_mod_section_prepend(mod, section);
1677        ret = ALIGN(*size, sechdr->sh_addralign ?: 1);
1678        *size = ret + sechdr->sh_size;
1679        return ret;
1680}
1681
1682/* Lay out the SHF_ALLOC sections in a way not dissimilar to how ld
1683   might -- code, read-only data, read-write data, small data.  Tally
1684   sizes, and place the offsets into sh_entsize fields: high bit means it
1685   belongs in init. */
1686static void layout_sections(struct module *mod,
1687                            const Elf_Ehdr *hdr,
1688                            Elf_Shdr *sechdrs,
1689                            const char *secstrings)
1690{
1691        static unsigned long const masks[][2] = {
1692                /* NOTE: all executable code must be the first section
1693                 * in this array; otherwise modify the text_size
1694                 * finder in the two loops below */
1695                { SHF_EXECINSTR | SHF_ALLOC, ARCH_SHF_SMALL },
1696                { SHF_ALLOC, SHF_WRITE | ARCH_SHF_SMALL },
1697                { SHF_WRITE | SHF_ALLOC, ARCH_SHF_SMALL },
1698                { ARCH_SHF_SMALL | SHF_ALLOC, 0 }
1699        };
1700        unsigned int m, i;
1701
1702        for (i = 0; i < hdr->e_shnum; i++)
1703                sechdrs[i].sh_entsize = ~0UL;
1704
1705        DEBUGP("Core section allocation order:\n");
1706        for (m = 0; m < ARRAY_SIZE(masks); ++m) {
1707                for (i = 0; i < hdr->e_shnum; ++i) {
1708                        Elf_Shdr *s = &sechdrs[i];
1709
1710                        if ((s->sh_flags & masks[m][0]) != masks[m][0]
1711                            || (s->sh_flags & masks[m][1])
1712                            || s->sh_entsize != ~0UL
1713                            || strstarts(secstrings + s->sh_name, ".init"))
1714                                continue;
1715                        s->sh_entsize = get_offset(mod, &mod->core_size, s, i);
1716                        DEBUGP("\t%s\n", secstrings + s->sh_name);
1717                }
1718                if (m == 0)
1719                        mod->core_text_size = mod->core_size;
1720        }
1721
1722        DEBUGP("Init section allocation order:\n");
1723        for (m = 0; m < ARRAY_SIZE(masks); ++m) {
1724                for (i = 0; i < hdr->e_shnum; ++i) {
1725                        Elf_Shdr *s = &sechdrs[i];
1726
1727                        if ((s->sh_flags & masks[m][0]) != masks[m][0]
1728                            || (s->sh_flags & masks[m][1])
1729                            || s->sh_entsize != ~0UL
1730                            || !strstarts(secstrings + s->sh_name, ".init"))
1731                                continue;
1732                        s->sh_entsize = (get_offset(mod, &mod->init_size, s, i)
1733                                         | INIT_OFFSET_MASK);
1734                        DEBUGP("\t%s\n", secstrings + s->sh_name);
1735                }
1736                if (m == 0)
1737                        mod->init_text_size = mod->init_size;
1738        }
1739}
1740
1741static void set_license(struct module *mod, const char *license)
1742{
1743        if (!license)
1744                license = "unspecified";
1745
1746        if (!license_is_gpl_compatible(license)) {
1747                if (!test_taint(TAINT_PROPRIETARY_MODULE))
1748                        printk(KERN_WARNING "%s: module license '%s' taints "
1749                                "kernel.\n", mod->name, license);
1750                add_taint_module(mod, TAINT_PROPRIETARY_MODULE);
1751        }
1752}
1753
1754/* Parse tag=value strings from .modinfo section */
1755static char *next_string(char *string, unsigned long *secsize)
1756{
1757        /* Skip non-zero chars */
1758        while (string[0]) {
1759                string++;
1760                if ((*secsize)-- <= 1)
1761                        return NULL;
1762        }
1763
1764        /* Skip any zero padding. */
1765        while (!string[0]) {
1766                string++;
1767                if ((*secsize)-- <= 1)
1768                        return NULL;
1769        }
1770        return string;
1771}
1772
1773static char *get_modinfo(Elf_Shdr *sechdrs,
1774                         unsigned int info,
1775                         const char *tag)
1776{
1777        char *p;
1778        unsigned int taglen = strlen(tag);
1779        unsigned long size = sechdrs[info].sh_size;
1780
1781        for (p = (char *)sechdrs[info].sh_addr; p; p = next_string(p, &size)) {
1782                if (strncmp(p, tag, taglen) == 0 && p[taglen] == '=')
1783                        return p + taglen + 1;
1784        }
1785        return NULL;
1786}
1787
1788static void setup_modinfo(struct module *mod, Elf_Shdr *sechdrs,
1789                          unsigned int infoindex)
1790{
1791        struct module_attribute *attr;
1792        int i;
1793
1794        for (i = 0; (attr = modinfo_attrs[i]); i++) {
1795                if (attr->setup)
1796                        attr->setup(mod,
1797                                    get_modinfo(sechdrs,
1798                                                infoindex,
1799                                                attr->attr.name));
1800        }
1801}
1802
1803static void free_modinfo(struct module *mod)
1804{
1805        struct module_attribute *attr;
1806        int i;
1807
1808        for (i = 0; (attr = modinfo_attrs[i]); i++) {
1809                if (attr->free)
1810                        attr->free(mod);
1811        }
1812}
1813
1814#ifdef CONFIG_KALLSYMS
1815
1816/* lookup symbol in given range of kernel_symbols */
1817static const struct kernel_symbol *lookup_symbol(const char *name,
1818        const struct kernel_symbol *start,
1819        const struct kernel_symbol *stop)
1820{
1821        const struct kernel_symbol *ks = start;
1822        for (; ks < stop; ks++)
1823                if (strcmp(ks->name, name) == 0)
1824                        return ks;
1825        return NULL;
1826}
1827
1828static int is_exported(const char *name, unsigned long value,
1829                       const struct module *mod)
1830{
1831        const struct kernel_symbol *ks;
1832        if (!mod)
1833                ks = lookup_symbol(name, __start___ksymtab, __stop___ksymtab);
1834        else
1835                ks = lookup_symbol(name, mod->syms, mod->syms + mod->num_syms);
1836        return ks != NULL && ks->value == value;
1837}
1838
1839/* As per nm */
1840static char elf_type(const Elf_Sym *sym,
1841                     Elf_Shdr *sechdrs,
1842                     const char *secstrings,
1843                     struct module *mod)
1844{
1845        if (ELF_ST_BIND(sym->st_info) == STB_WEAK) {
1846                if (ELF_ST_TYPE(sym->st_info) == STT_OBJECT)
1847                        return 'v';
1848                else
1849                        return 'w';
1850        }
1851        if (sym->st_shndx == SHN_UNDEF)
1852                return 'U';
1853        if (sym->st_shndx == SHN_ABS)
1854                return 'a';
1855        if (sym->st_shndx >= SHN_LORESERVE)
1856                return '?';
1857        if (sechdrs[sym->st_shndx].sh_flags & SHF_EXECINSTR)
1858                return 't';
1859        if (sechdrs[sym->st_shndx].sh_flags & SHF_ALLOC
1860            && sechdrs[sym->st_shndx].sh_type != SHT_NOBITS) {
1861                if (!(sechdrs[sym->st_shndx].sh_flags & SHF_WRITE))
1862                        return 'r';
1863                else if (sechdrs[sym->st_shndx].sh_flags & ARCH_SHF_SMALL)
1864                        return 'g';
1865                else
1866                        return 'd';
1867        }
1868        if (sechdrs[sym->st_shndx].sh_type == SHT_NOBITS) {
1869                if (sechdrs[sym->st_shndx].sh_flags & ARCH_SHF_SMALL)
1870                        return 's';
1871                else
1872                        return 'b';
1873        }
1874        if (strstarts(secstrings + sechdrs[sym->st_shndx].sh_name, ".debug"))
1875                return 'n';
1876        return '?';
1877}
1878
1879static bool is_core_symbol(const Elf_Sym *src, const Elf_Shdr *sechdrs,
1880                           unsigned int shnum)
1881{
1882        const Elf_Shdr *sec;
1883
1884        if (src->st_shndx == SHN_UNDEF
1885            || src->st_shndx >= shnum
1886            || !src->st_name)
1887                return false;
1888
1889        sec = sechdrs + src->st_shndx;
1890        if (!(sec->sh_flags & SHF_ALLOC)
1891#ifndef CONFIG_KALLSYMS_ALL
1892            || !(sec->sh_flags & SHF_EXECINSTR)
1893#endif
1894            || (sec->sh_entsize & INIT_OFFSET_MASK))
1895                return false;
1896
1897        return true;
1898}
1899
1900static unsigned long layout_symtab(struct module *mod,
1901                                   Elf_Shdr *sechdrs,
1902                                   unsigned int symindex,
1903                                   unsigned int strindex,
1904                                   const Elf_Ehdr *hdr,
1905                                   const char *secstrings,
1906                                   unsigned long *pstroffs,
1907                                   unsigned long *strmap)
1908{
1909        unsigned long symoffs;
1910        Elf_Shdr *symsect = sechdrs + symindex;
1911        Elf_Shdr *strsect = sechdrs + strindex;
1912        const Elf_Sym *src;
1913        const char *strtab;
1914        unsigned int i, nsrc, ndst;
1915
1916        /* Put symbol section at end of init part of module. */
1917        symsect->sh_flags |= SHF_ALLOC;
1918        symsect->sh_entsize = get_offset(mod, &mod->init_size, symsect,
1919                                         symindex) | INIT_OFFSET_MASK;
1920        DEBUGP("\t%s\n", secstrings + symsect->sh_name);
1921
1922        src = (void *)hdr + symsect->sh_offset;
1923        nsrc = symsect->sh_size / sizeof(*src);
1924        strtab = (void *)hdr + strsect->sh_offset;
1925        for (ndst = i = 1; i < nsrc; ++i, ++src)
1926                if (is_core_symbol(src, sechdrs, hdr->e_shnum)) {
1927                        unsigned int j = src->st_name;
1928
1929                        while(!__test_and_set_bit(j, strmap) && strtab[j])
1930                                ++j;
1931                        ++ndst;
1932                }
1933
1934        /* Append room for core symbols at end of core part. */
1935        symoffs = ALIGN(mod->core_size, symsect->sh_addralign ?: 1);
1936        mod->core_size = symoffs + ndst * sizeof(Elf_Sym);
1937
1938        /* Put string table section at end of init part of module. */
1939        strsect->sh_flags |= SHF_ALLOC;
1940        strsect->sh_entsize = get_offset(mod, &mod->init_size, strsect,
1941                                         strindex) | INIT_OFFSET_MASK;
1942        DEBUGP("\t%s\n", secstrings + strsect->sh_name);
1943
1944        /* Append room for core symbols' strings at end of core part. */
1945        *pstroffs = mod->core_size;
1946        __set_bit(0, strmap);
1947        mod->core_size += bitmap_weight(strmap, strsect->sh_size);
1948
1949        return symoffs;
1950}
1951
1952static void add_kallsyms(struct module *mod,
1953                         Elf_Shdr *sechdrs,
1954                         unsigned int shnum,
1955                         unsigned int symindex,
1956                         unsigned int strindex,
1957                         unsigned long symoffs,
1958                         unsigned long stroffs,
1959                         const char *secstrings,
1960                         unsigned long *strmap)
1961{
1962        unsigned int i, ndst;
1963        const Elf_Sym *src;
1964        Elf_Sym *dst;
1965        char *s;
1966
1967        mod->symtab = (void *)sechdrs[symindex].sh_addr;
1968        mod->num_symtab = sechdrs[symindex].sh_size / sizeof(Elf_Sym);
1969        mod->strtab = (void *)sechdrs[strindex].sh_addr;
1970
1971        /* Set types up while we still have access to sections. */
1972        for (i = 0; i < mod->num_symtab; i++)
1973                mod->symtab[i].st_info
1974                        = elf_type(&mod->symtab[i], sechdrs, secstrings, mod);
1975
1976        mod->core_symtab = dst = mod->module_core + symoffs;
1977        src = mod->symtab;
1978        *dst = *src;
1979        for (ndst = i = 1; i < mod->num_symtab; ++i, ++src) {
1980                if (!is_core_symbol(src, sechdrs, shnum))
1981                        continue;
1982                dst[ndst] = *src;
1983                dst[ndst].st_name = bitmap_weight(strmap, dst[ndst].st_name);
1984                ++ndst;
1985        }
1986        mod->core_num_syms = ndst;
1987
1988        mod->core_strtab = s = mod->module_core + stroffs;
1989        for (*s = 0, i = 1; i < sechdrs[strindex].sh_size; ++i)
1990                if (test_bit(i, strmap))
1991                        *++s = mod->strtab[i];
1992}
1993#else
1994static inline unsigned long layout_symtab(struct module *mod,
1995                                          Elf_Shdr *sechdrs,
1996                                          unsigned int symindex,
1997                                          unsigned int strindex,
1998                                          const Elf_Ehdr *hdr,
1999                                          const char *secstrings,
2000                                          unsigned long *pstroffs,
2001                                          unsigned long *strmap)
2002{
2003        return 0;
2004}
2005
2006static inline void add_kallsyms(struct module *mod,
2007                                Elf_Shdr *sechdrs,
2008                                unsigned int shnum,
2009                                unsigned int symindex,
2010                                unsigned int strindex,
2011                                unsigned long symoffs,
2012                                unsigned long stroffs,
2013                                const char *secstrings,
2014                                const unsigned long *strmap)
2015{
2016}
2017#endif /* CONFIG_KALLSYMS */
2018
2019static void dynamic_debug_setup(struct _ddebug *debug, unsigned int num)
2020{
2021#ifdef CONFIG_DYNAMIC_DEBUG
2022        if (ddebug_add_module(debug, num, debug->modname))
2023                printk(KERN_ERR "dynamic debug error adding module: %s\n",
2024                                        debug->modname);
2025#endif
2026}
2027
2028static void *module_alloc_update_bounds(unsigned long size)
2029{
2030        void *ret = module_alloc(size);
2031
2032        if (ret) {
2033                /* Update module bounds. */
2034                if ((unsigned long)ret < module_addr_min)
2035                        module_addr_min = (unsigned long)ret;
2036                if ((unsigned long)ret + size > module_addr_max)
2037                        module_addr_max = (unsigned long)ret + size;
2038        }
2039        return ret;
2040}
2041
2042#ifdef CONFIG_DEBUG_KMEMLEAK
2043static void kmemleak_load_module(struct module *mod, Elf_Ehdr *hdr,
2044                                 Elf_Shdr *sechdrs, char *secstrings)
2045{
2046        unsigned int i;
2047
2048        /* only scan the sections containing data */
2049        kmemleak_scan_area(mod->module_core, (unsigned long)mod -
2050                           (unsigned long)mod->module_core,
2051                           sizeof(struct module), GFP_KERNEL);
2052
2053        for (i = 1; i < hdr->e_shnum; i++) {
2054                if (!(sechdrs[i].sh_flags & SHF_ALLOC))
2055                        continue;
2056                if (strncmp(secstrings + sechdrs[i].sh_name, ".data", 5) != 0
2057                    && strncmp(secstrings + sechdrs[i].sh_name, ".bss", 4) != 0)
2058                        continue;
2059
2060                kmemleak_scan_area(mod->module_core, sechdrs[i].sh_addr -
2061                                   (unsigned long)mod->module_core,
2062                                   sechdrs[i].sh_size, GFP_KERNEL);
2063        }
2064}
2065#else
2066static inline void kmemleak_load_module(struct module *mod, Elf_Ehdr *hdr,
2067                                        Elf_Shdr *sechdrs, char *secstrings)
2068{
2069}
2070#endif
2071
2072/* Allocate and load the module: note that size of section 0 is always
2073   zero, and we rely on this for optional sections. */
2074static noinline struct module *load_module(void __user *umod,
2075                                  unsigned long len,
2076                                  const char __user *uargs)
2077{
2078        Elf_Ehdr *hdr;
2079        Elf_Shdr *sechdrs;
2080        char *secstrings, *args, *modmagic, *strtab = NULL;
2081        char *staging;
2082        unsigned int i;
2083        unsigned int symindex = 0;
2084        unsigned int strindex = 0;
2085        unsigned int modindex, versindex, infoindex, pcpuindex;
2086        struct module *mod;
2087        long err = 0;
2088        void *percpu = NULL, *ptr = NULL; /* Stops spurious gcc warning */
2089        unsigned long symoffs, stroffs, *strmap;
2090
2091        mm_segment_t old_fs;
2092
2093        DEBUGP("load_module: umod=%p, len=%lu, uargs=%p\n",
2094               umod, len, uargs);
2095        if (len < sizeof(*hdr))
2096                return ERR_PTR(-ENOEXEC);
2097
2098        /* Suck in entire file: we'll want most of it. */
2099        /* vmalloc barfs on "unusual" numbers.  Check here */
2100        if (len > 64 * 1024 * 1024 || (hdr = vmalloc(len)) == NULL)
2101                return ERR_PTR(-ENOMEM);
2102
2103        if (copy_from_user(hdr, umod, len) != 0) {
2104                err = -EFAULT;
2105                goto free_hdr;
2106        }
2107
2108        /* Sanity checks against insmoding binaries or wrong arch,
2109           weird elf version */
2110        if (memcmp(hdr->e_ident, ELFMAG, SELFMAG) != 0
2111            || hdr->e_type != ET_REL
2112            || !elf_check_arch(hdr)
2113            || hdr->e_shentsize != sizeof(*sechdrs)) {
2114                err = -ENOEXEC;
2115                goto free_hdr;
2116        }
2117
2118        if (len < hdr->e_shoff + hdr->e_shnum * sizeof(Elf_Shdr))
2119                goto truncated;
2120
2121        /* Convenience variables */
2122        sechdrs = (void *)hdr + hdr->e_shoff;
2123        secstrings = (void *)hdr + sechdrs[hdr->e_shstrndx].sh_offset;
2124        sechdrs[0].sh_addr = 0;
2125
2126        for (i = 1; i < hdr->e_shnum; i++) {
2127                if (sechdrs[i].sh_type != SHT_NOBITS
2128                    && len < sechdrs[i].sh_offset + sechdrs[i].sh_size)
2129                        goto truncated;
2130
2131                /* Mark all sections sh_addr with their address in the
2132                   temporary image. */
2133                sechdrs[i].sh_addr = (size_t)hdr + sechdrs[i].sh_offset;
2134
2135                /* Internal symbols and strings. */
2136                if (sechdrs[i].sh_type == SHT_SYMTAB) {
2137                        symindex = i;
2138                        strindex = sechdrs[i].sh_link;
2139                        strtab = (char *)hdr + sechdrs[strindex].sh_offset;
2140                }
2141#ifndef CONFIG_MODULE_UNLOAD
2142                /* Don't load .exit sections */
2143                if (strstarts(secstrings+sechdrs[i].sh_name, ".exit"))
2144                        sechdrs[i].sh_flags &= ~(unsigned long)SHF_ALLOC;
2145#endif
2146        }
2147
2148        modindex = find_sec(hdr, sechdrs, secstrings,
2149                            ".gnu.linkonce.this_module");
2150        if (!modindex) {
2151                printk(KERN_WARNING "No module found in object\n");
2152                err = -ENOEXEC;
2153                goto free_hdr;
2154        }
2155        /* This is temporary: point mod into copy of data. */
2156        mod = (void *)sechdrs[modindex].sh_addr;
2157
2158        if (symindex == 0) {
2159                printk(KERN_WARNING "%s: module has no symbols (stripped?)\n",
2160                       mod->name);
2161                err = -ENOEXEC;
2162                goto free_hdr;
2163        }
2164
2165        versindex = find_sec(hdr, sechdrs, secstrings, "__versions");
2166        infoindex = find_sec(hdr, sechdrs, secstrings, ".modinfo");
2167        pcpuindex = find_pcpusec(hdr, sechdrs, secstrings);
2168
2169        /* Don't keep modinfo and version sections. */
2170        sechdrs[infoindex].sh_flags &= ~(unsigned long)SHF_ALLOC;
2171        sechdrs[versindex].sh_flags &= ~(unsigned long)SHF_ALLOC;
2172
2173        /* Check module struct version now, before we try to use module. */
2174        if (!check_modstruct_version(sechdrs, versindex, mod)) {
2175                err = -ENOEXEC;
2176                goto free_hdr;
2177        }
2178
2179        modmagic = get_modinfo(sechdrs, infoindex, "vermagic");
2180        /* This is allowed: modprobe --force will invalidate it. */
2181        if (!modmagic) {
2182                err = try_to_force_load(mod, "bad vermagic");
2183                if (err)
2184                        goto free_hdr;
2185        } else if (!same_magic(modmagic, vermagic, versindex)) {
2186                printk(KERN_ERR "%s: version magic '%s' should be '%s'\n",
2187                       mod->name, modmagic, vermagic);
2188                err = -ENOEXEC;
2189                goto free_hdr;
2190        }
2191
2192        staging = get_modinfo(sechdrs, infoindex, "staging");
2193        if (staging) {
2194                add_taint_module(mod, TAINT_CRAP);
2195                printk(KERN_WARNING "%s: module is from the staging directory,"
2196                       " the quality is unknown, you have been warned.\n",
2197                       mod->name);
2198        }
2199
2200        /* Now copy in args */
2201        args = strndup_user(uargs, ~0UL >> 1);
2202        if (IS_ERR(args)) {
2203                err = PTR_ERR(args);
2204                goto free_hdr;
2205        }
2206
2207        strmap = kzalloc(BITS_TO_LONGS(sechdrs[strindex].sh_size)
2208                         * sizeof(long), GFP_KERNEL);
2209        if (!strmap) {
2210                err = -ENOMEM;
2211                goto free_mod;
2212        }
2213
2214        if (find_module(mod->name)) {
2215                err = -EEXIST;
2216                goto free_mod;
2217        }
2218
2219        mod->state = MODULE_STATE_COMING;
2220
2221        /* Allow arches to frob section contents and sizes.  */
2222        err = module_frob_arch_sections(hdr, sechdrs, secstrings, mod);
2223        if (err < 0)
2224                goto free_mod;
2225
2226        if (pcpuindex) {
2227                /* We have a special allocation for this section. */
2228                percpu = percpu_modalloc(sechdrs[pcpuindex].sh_size,
2229                                         sechdrs[pcpuindex].sh_addralign,
2230                                         mod->name);
2231                if (!percpu) {
2232                        err = -ENOMEM;
2233                        goto free_mod;
2234                }
2235                sechdrs[pcpuindex].sh_flags &= ~(unsigned long)SHF_ALLOC;
2236                mod->percpu = percpu;
2237        }
2238
2239        /* Determine total sizes, and put offsets in sh_entsize.  For now
2240           this is done generically; there doesn't appear to be any
2241           special cases for the architectures. */
2242        layout_sections(mod, hdr, sechdrs, secstrings);
2243        symoffs = layout_symtab(mod, sechdrs, symindex, strindex, hdr,
2244                                secstrings, &stroffs, strmap);
2245
2246        /* Do the allocs. */
2247        ptr = module_alloc_update_bounds(mod->core_size);
2248        /*
2249         * The pointer to this block is stored in the module structure
2250         * which is inside the block. Just mark it as not being a
2251         * leak.
2252         */
2253        kmemleak_not_leak(ptr);
2254        if (!ptr) {
2255                err = -ENOMEM;
2256                goto free_percpu;
2257        }
2258        memset(ptr, 0, mod->core_size);
2259        mod->module_core = ptr;
2260
2261        ptr = module_alloc_update_bounds(mod->init_size);
2262        /*
2263         * The pointer to this block is stored in the module structure
2264         * which is inside the block. This block doesn't need to be
2265         * scanned as it contains data and code that will be freed
2266         * after the module is initialized.
2267         */
2268        kmemleak_ignore(ptr);
2269        if (!ptr && mod->init_size) {
2270                err = -ENOMEM;
2271                goto free_core;
2272        }
2273        memset(ptr, 0, mod->init_size);
2274        mod->module_init = ptr;
2275
2276        /* Transfer each section which specifies SHF_ALLOC */
2277        DEBUGP("final section addresses:\n");
2278        for (i = 0; i < hdr->e_shnum; i++) {
2279                void *dest;
2280
2281                if (!(sechdrs[i].sh_flags & SHF_ALLOC))
2282                        continue;
2283
2284                if (sechdrs[i].sh_entsize & INIT_OFFSET_MASK)
2285                        dest = mod->module_init
2286                                + (sechdrs[i].sh_entsize & ~INIT_OFFSET_MASK);
2287                else
2288                        dest = mod->module_core + sechdrs[i].sh_entsize;
2289
2290                if (sechdrs[i].sh_type != SHT_NOBITS)
2291                        memcpy(dest, (void *)sechdrs[i].sh_addr,
2292                               sechdrs[i].sh_size);
2293                /* Update sh_addr to point to copy in image. */
2294                sechdrs[i].sh_addr = (unsigned long)dest;
2295                DEBUGP("\t0x%lx %s\n", sechdrs[i].sh_addr, secstrings + sechdrs[i].sh_name);
2296        }
2297        /* Module has been moved. */
2298        mod = (void *)sechdrs[modindex].sh_addr;
2299        kmemleak_load_module(mod, hdr, sechdrs, secstrings);
2300
2301#if defined(CONFIG_MODULE_UNLOAD) && defined(CONFIG_SMP)
2302        mod->refptr = percpu_modalloc(sizeof(local_t), __alignof__(local_t),
2303                                      mod->name);
2304        if (!mod->refptr) {
2305                err = -ENOMEM;
2306                goto free_init;
2307        }
2308#endif
2309        /* Now we've moved module, initialize linked lists, etc. */
2310        module_unload_init(mod);
2311
2312        /* add kobject, so we can reference it. */
2313        err = mod_sysfs_init(mod);
2314        if (err)
2315                goto free_unload;
2316
2317        /* Set up license info based on the info section */
2318        set_license(mod, get_modinfo(sechdrs, infoindex, "license"));
2319
2320        /*
2321         * ndiswrapper is under GPL by itself, but loads proprietary modules.
2322         * Don't use add_taint_module(), as it would prevent ndiswrapper from
2323         * using GPL-only symbols it needs.
2324         */
2325        if (strcmp(mod->name, "ndiswrapper") == 0)
2326                add_taint(TAINT_PROPRIETARY_MODULE);
2327
2328        /* driverloader was caught wrongly pretending to be under GPL */
2329        if (strcmp(mod->name, "driverloader") == 0)
2330                add_taint_module(mod, TAINT_PROPRIETARY_MODULE);
2331
2332        /* Set up MODINFO_ATTR fields */
2333        setup_modinfo(mod, sechdrs, infoindex);
2334
2335        /* Fix up syms, so that st_value is a pointer to location. */
2336        err = simplify_symbols(sechdrs, symindex, strtab, versindex, pcpuindex,
2337                               mod);
2338        if (err < 0)
2339                goto cleanup;
2340
2341        /* Now we've got everything in the final locations, we can
2342         * find optional sections. */
2343        mod->kp = section_objs(hdr, sechdrs, secstrings, "__param",
2344                               sizeof(*mod->kp), &mod->num_kp);
2345        mod->syms = section_objs(hdr, sechdrs, secstrings, "__ksymtab",
2346                                 sizeof(*mod->syms), &mod->num_syms);
2347        mod->crcs = section_addr(hdr, sechdrs, secstrings, "__kcrctab");
2348        mod->gpl_syms = section_objs(hdr, sechdrs, secstrings, "__ksymtab_gpl",
2349                                     sizeof(*mod->gpl_syms),
2350                                     &mod->num_gpl_syms);
2351        mod->gpl_crcs = section_addr(hdr, sechdrs, secstrings, "__kcrctab_gpl");
2352        mod->gpl_future_syms = section_objs(hdr, sechdrs, secstrings,
2353                                            "__ksymtab_gpl_future",
2354                                            sizeof(*mod->gpl_future_syms),
2355                                            &mod->num_gpl_future_syms);
2356        mod->gpl_future_crcs = section_addr(hdr, sechdrs, secstrings,
2357                                            "__kcrctab_gpl_future");
2358
2359#ifdef CONFIG_UNUSED_SYMBOLS
2360        mod->unused_syms = section_objs(hdr, sechdrs, secstrings,
2361                                        "__ksymtab_unused",
2362                                        sizeof(*mod->unused_syms),
2363                                        &mod->num_unused_syms);
2364        mod->unused_crcs = section_addr(hdr, sechdrs, secstrings,
2365                                        "__kcrctab_unused");
2366        mod->unused_gpl_syms = section_objs(hdr, sechdrs, secstrings,
2367                                            "__ksymtab_unused_gpl",
2368                                            sizeof(*mod->unused_gpl_syms),
2369                                            &mod->num_unused_gpl_syms);
2370        mod->unused_gpl_crcs = section_addr(hdr, sechdrs, secstrings,
2371                                            "__kcrctab_unused_gpl");
2372#endif
2373#ifdef CONFIG_CONSTRUCTORS
2374        mod->ctors = section_objs(hdr, sechdrs, secstrings, ".ctors",
2375                                  sizeof(*mod->ctors), &mod->num_ctors);
2376#endif
2377
2378#ifdef CONFIG_TRACEPOINTS
2379        mod->tracepoints = section_objs(hdr, sechdrs, secstrings,
2380                                        "__tracepoints",
2381                                        sizeof(*mod->tracepoints),
2382                                        &mod->num_tracepoints);
2383#endif
2384#ifdef CONFIG_EVENT_TRACING
2385        mod->trace_events = section_objs(hdr, sechdrs, secstrings,
2386                                         "_ftrace_events",
2387                                         sizeof(*mod->trace_events),
2388                                         &mod->num_trace_events);
2389#endif
2390#ifdef CONFIG_FTRACE_MCOUNT_RECORD
2391        /* sechdrs[0].sh_size is always zero */
2392        mod->ftrace_callsites = section_objs(hdr, sechdrs, secstrings,
2393                                             "__mcount_loc",
2394                                             sizeof(*mod->ftrace_callsites),
2395                                             &mod->num_ftrace_callsites);
2396#endif
2397#ifdef CONFIG_MODVERSIONS
2398        if ((mod->num_syms && !mod->crcs)
2399            || (mod->num_gpl_syms && !mod->gpl_crcs)
2400            || (mod->num_gpl_future_syms && !mod->gpl_future_crcs)
2401#ifdef CONFIG_UNUSED_SYMBOLS
2402            || (mod->num_unused_syms && !mod->unused_crcs)
2403            || (mod->num_unused_gpl_syms && !mod->unused_gpl_crcs)
2404#endif
2405                ) {
2406                err = try_to_force_load(mod,
2407                                        "no versions for exported symbols");
2408                if (err)
2409                        goto cleanup;
2410        }
2411#endif
2412
2413        /* Now do relocations. */
2414        for (i = 1; i < hdr->e_shnum; i++) {
2415                const char *strtab = (char *)sechdrs[strindex].sh_addr;
2416                unsigned int info = sechdrs[i].sh_info;
2417
2418                /* Not a valid relocation section? */
2419                if (info >= hdr->e_shnum)
2420                        continue;
2421
2422                /* Don't bother with non-allocated sections */
2423                if (!(sechdrs[info].sh_flags & SHF_ALLOC))
2424                        continue;
2425
2426                if (sechdrs[i].sh_type == SHT_REL)
2427                        err = apply_relocate(sechdrs, strtab, symindex, i,mod);
2428                else if (sechdrs[i].sh_type == SHT_RELA)
2429                        err = apply_relocate_add(sechdrs, strtab, symindex, i,
2430                                                 mod);
2431                if (err < 0)
2432                        goto cleanup;
2433        }
2434
2435        /* Find duplicate symbols */
2436        err = verify_export_symbols(mod);
2437        if (err < 0)
2438                goto cleanup;
2439
2440        /* Set up and sort exception table */
2441        mod->extable = section_objs(hdr, sechdrs, secstrings, "__ex_table",
2442                                    sizeof(*mod->extable), &mod->num_exentries);
2443        sort_extable(mod->extable, mod->extable + mod->num_exentries);
2444
2445        /* Finally, copy percpu area over. */
2446        percpu_modcopy(mod->percpu, (void *)sechdrs[pcpuindex].sh_addr,
2447                       sechdrs[pcpuindex].sh_size);
2448
2449        add_kallsyms(mod, sechdrs, hdr->e_shnum, symindex, strindex,
2450                     symoffs, stroffs, secstrings, strmap);
2451        kfree(strmap);
2452        strmap = NULL;
2453
2454        if (!mod->taints) {
2455                struct _ddebug *debug;
2456                unsigned int num_debug;
2457
2458                debug = section_objs(hdr, sechdrs, secstrings, "__verbose",
2459                                     sizeof(*debug), &num_debug);
2460                if (debug)
2461                        dynamic_debug_setup(debug, num_debug);
2462        }
2463
2464        err = module_finalize(hdr, sechdrs, mod);
2465        if (err < 0)
2466                goto cleanup;
2467
2468        /* flush the icache in correct context */
2469        old_fs = get_fs();
2470        set_fs(KERNEL_DS);
2471
2472        /*
2473         * Flush the instruction cache, since we've played with text.
2474         * Do it before processing of module parameters, so the module
2475         * can provide parameter accessor functions of its own.
2476         */
2477        if (mod->module_init)
2478                flush_icache_range((unsigned long)mod->module_init,
2479                                   (unsigned long)mod->module_init
2480                                   + mod->init_size);
2481        flush_icache_range((unsigned long)mod->module_core,
2482                           (unsigned long)mod->module_core + mod->core_size);
2483
2484        set_fs(old_fs);
2485
2486        mod->args = args;
2487        if (section_addr(hdr, sechdrs, secstrings, "__obsparm"))
2488                printk(KERN_WARNING "%s: Ignoring obsolete parameters\n",
2489                       mod->name);
2490
2491        /* Now sew it into the lists so we can get lockdep and oops
2492         * info during argument parsing.  Noone should access us, since
2493         * strong_try_module_get() will fail.
2494         * lockdep/oops can run asynchronous, so use the RCU list insertion
2495         * function to insert in a way safe to concurrent readers.
2496         * The mutex protects against concurrent writers.
2497         */
2498        list_add_rcu(&mod->list, &modules);
2499
2500        err = parse_args(mod->name, mod->args, mod->kp, mod->num_kp, NULL);
2501        if (err < 0)
2502                goto unlink;
2503
2504        err = mod_sysfs_setup(mod, mod->kp, mod->num_kp);
2505        if (err < 0)
2506                goto unlink;
2507        add_sect_attrs(mod, hdr->e_shnum, secstrings, sechdrs);
2508        add_notes_attrs(mod, hdr->e_shnum, secstrings, sechdrs);
2509
2510        /* Get rid of temporary copy */
2511        vfree(hdr);
2512
2513        trace_module_load(mod);
2514
2515        /* Done! */
2516        return mod;
2517
2518 unlink:
2519        /* Unlink carefully: kallsyms could be walking list. */
2520        list_del_rcu(&mod->list);
2521        synchronize_sched();
2522        module_arch_cleanup(mod);
2523 cleanup:
2524        free_modinfo(mod);
2525        kobject_del(&mod->mkobj.kobj);
2526        kobject_put(&mod->mkobj.kobj);
2527 free_unload:
2528        module_unload_free(mod);
2529#if defined(CONFIG_MODULE_UNLOAD) && defined(CONFIG_SMP)
2530        percpu_modfree(mod->refptr);
2531 free_init:
2532#endif
2533        module_free(mod, mod->module_init);
2534 free_core:
2535        module_free(mod, mod->module_core);
2536        /* mod will be freed with core. Don't access it beyond this line! */
2537 free_percpu:
2538        if (percpu)
2539                percpu_modfree(percpu);
2540 free_mod:
2541        kfree(args);
2542        kfree(strmap);
2543 free_hdr:
2544        vfree(hdr);
2545        return ERR_PTR(err);
2546
2547 truncated:
2548        printk(KERN_ERR "Module len %lu truncated\n", len);
2549        err = -ENOEXEC;
2550        goto free_hdr;
2551}
2552
2553/* Call module constructors. */
2554static void do_mod_ctors(struct module *mod)
2555{
2556#ifdef CONFIG_CONSTRUCTORS
2557        unsigned long i;
2558
2559        for (i = 0; i < mod->num_ctors; i++)
2560                mod->ctors[i]();
2561#endif
2562}
2563
2564/* This is where the real work happens */
2565SYSCALL_DEFINE3(init_module, void __user *, umod,
2566                unsigned long, len, const char __user *, uargs)
2567{
2568        struct module *mod;
2569        int ret = 0;
2570
2571        /* Must have permission */
2572        if (!capable(CAP_SYS_MODULE) || modules_disabled)
2573                return -EPERM;
2574
2575        /* Only one module load at a time, please */
2576        if (mutex_lock_interruptible(&module_mutex) != 0)
2577                return -EINTR;
2578
2579        /* Do all the hard work */
2580        mod = load_module(umod, len, uargs);
2581        if (IS_ERR(mod)) {
2582                mutex_unlock(&module_mutex);
2583                return PTR_ERR(mod);
2584        }
2585
2586        /* Drop lock so they can recurse */
2587        mutex_unlock(&module_mutex);
2588
2589        blocking_notifier_call_chain(&module_notify_list,
2590                        MODULE_STATE_COMING, mod);
2591
2592        do_mod_ctors(mod);
2593        /* Start the module */
2594        if (mod->init != NULL)
2595                ret = do_one_initcall(mod->init);
2596        if (ret < 0) {
2597                /* Init routine failed: abort.  Try to protect us from
2598                   buggy refcounters. */
2599                mod->state = MODULE_STATE_GOING;
2600                synchronize_sched();
2601                module_put(mod);
2602                blocking_notifier_call_chain(&module_notify_list,
2603                                             MODULE_STATE_GOING, mod);
2604                mutex_lock(&module_mutex);
2605                free_module(mod);
2606                mutex_unlock(&module_mutex);
2607                wake_up(&module_wq);
2608                return ret;
2609        }
2610        if (ret > 0) {
2611                printk(KERN_WARNING
2612"%s: '%s'->init suspiciously returned %d, it should follow 0/-E convention\n"
2613"%s: loading module anyway...\n",
2614                       __func__, mod->name, ret,
2615                       __func__);
2616                dump_stack();
2617        }
2618
2619        /* Now it's a first class citizen!  Wake up anyone waiting for it. */
2620        mod->state = MODULE_STATE_LIVE;
2621        wake_up(&module_wq);
2622        blocking_notifier_call_chain(&module_notify_list,
2623                                     MODULE_STATE_LIVE, mod);
2624
2625        /* We need to finish all async code before the module init sequence is done */
2626        async_synchronize_full();
2627
2628        mutex_lock(&module_mutex);
2629        /* Drop initial reference. */
2630        module_put(mod);
2631        trim_init_extable(mod);
2632#ifdef CONFIG_KALLSYMS
2633        mod->num_symtab = mod->core_num_syms;
2634        mod->symtab = mod->core_symtab;
2635        mod->strtab = mod->core_strtab;
2636#endif
2637        module_free(mod, mod->module_init);
2638        mod->module_init = NULL;
2639        mod->init_size = 0;
2640        mod->init_text_size = 0;
2641        mutex_unlock(&module_mutex);
2642
2643        return 0;
2644}
2645
2646static inline int within(unsigned long addr, void *start, unsigned long size)
2647{
2648        return ((void *)addr >= start && (void *)addr < start + size);
2649}
2650
2651#ifdef CONFIG_KALLSYMS
2652/*
2653 * This ignores the intensely annoying "mapping symbols" found
2654 * in ARM ELF files: $a, $t and $d.
2655 */
2656static inline int is_arm_mapping_symbol(const char *str)
2657{
2658        return str[0] == '$' && strchr("atd", str[1])
2659               && (str[2] == '\0' || str[2] == '.');
2660}
2661
2662static const char *get_ksymbol(struct module *mod,
2663                               unsigned long addr,
2664                               unsigned long *size,
2665                               unsigned long *offset)
2666{
2667        unsigned int i, best = 0;
2668        unsigned long nextval;
2669
2670        /* At worse, next value is at end of module */
2671        if (within_module_init(addr, mod))
2672                nextval = (unsigned long)mod->module_init+mod->init_text_size;
2673        else
2674                nextval = (unsigned long)mod->module_core+mod->core_text_size;
2675
2676        /* Scan for closest preceeding symbol, and next symbol. (ELF
2677           starts real symbols at 1). */
2678        for (i = 1; i < mod->num_symtab; i++) {
2679                if (mod->symtab[i].st_shndx == SHN_UNDEF)
2680                        continue;
2681
2682                /* We ignore unnamed symbols: they're uninformative
2683                 * and inserted at a whim. */
2684                if (mod->symtab[i].st_value <= addr
2685                    && mod->symtab[i].st_value > mod->symtab[best].st_value
2686                    && *(mod->strtab + mod->symtab[i].st_name) != '\0'
2687                    && !is_arm_mapping_symbol(mod->strtab + mod->symtab[i].st_name))
2688                        best = i;
2689                if (mod->symtab[i].st_value > addr
2690                    && mod->symtab[i].st_value < nextval
2691                    && *(mod->strtab + mod->symtab[i].st_name) != '\0'
2692                    && !is_arm_mapping_symbol(mod->strtab + mod->symtab[i].st_name))
2693                        nextval = mod->symtab[i].st_value;
2694        }
2695
2696        if (!best)
2697                return NULL;
2698
2699        if (size)
2700                *size = nextval - mod->symtab[best].st_value;
2701        if (offset)
2702                *offset = addr - mod->symtab[best].st_value;
2703        return mod->strtab + mod->symtab[best].st_name;
2704}
2705
2706/* For kallsyms to ask for address resolution.  NULL means not found.  Careful
2707 * not to lock to avoid deadlock on oopses, simply disable preemption. */
2708const char *module_address_lookup(unsigned long addr,
2709                            unsigned long *size,
2710                            unsigned long *offset,
2711                            char **modname,
2712                            char *namebuf)
2713{
2714        struct module *mod;
2715        const char *ret = NULL;
2716
2717        preempt_disable();
2718        list_for_each_entry_rcu(mod, &modules, list) {
2719                if (within_module_init(addr, mod) ||
2720                    within_module_core(addr, mod)) {
2721                        if (modname)
2722                                *modname = mod->name;
2723                        ret = get_ksymbol(mod, addr, size, offset);
2724                        break;
2725                }
2726        }
2727        /* Make a copy in here where it's safe */
2728        if (ret) {
2729                strncpy(namebuf, ret, KSYM_NAME_LEN - 1);
2730                ret = namebuf;
2731        }
2732        preempt_enable();
2733        return ret;
2734}
2735
2736int lookup_module_symbol_name(unsigned long addr, char *symname)
2737{
2738        struct module *mod;
2739
2740        preempt_disable();
2741        list_for_each_entry_rcu(mod, &modules, list) {
2742                if (within_module_init(addr, mod) ||
2743                    within_module_core(addr, mod)) {
2744                        const char *sym;
2745
2746                        sym = get_ksymbol(mod, addr, NULL, NULL);
2747                        if (!sym)
2748                                goto out;
2749                        strlcpy(symname, sym, KSYM_NAME_LEN);
2750                        preempt_enable();
2751                        return 0;
2752                }
2753        }
2754out:
2755        preempt_enable();
2756        return -ERANGE;
2757}
2758
2759int lookup_module_symbol_attrs(unsigned long addr, unsigned long *size,
2760                        unsigned long *offset, char *modname, char *name)
2761{
2762        struct module *mod;
2763
2764        preempt_disable();
2765        list_for_each_entry_rcu(mod, &modules, list) {
2766                if (within_module_init(addr, mod) ||
2767                    within_module_core(addr, mod)) {
2768                        const char *sym;
2769
2770                        sym = get_ksymbol(mod, addr, size, offset);
2771                        if (!sym)
2772                                goto out;
2773                        if (modname)
2774                                strlcpy(modname, mod->name, MODULE_NAME_LEN);
2775                        if (name)
2776                                strlcpy(name, sym, KSYM_NAME_LEN);
2777                        preempt_enable();
2778                        return 0;
2779                }
2780        }
2781out:
2782        preempt_enable();
2783        return -ERANGE;
2784}
2785
2786int module_get_kallsym(unsigned int symnum, unsigned long *value, char *type,
2787                        char *name, char *module_name, int *exported)
2788{
2789        struct module *mod;
2790
2791        preempt_disable();
2792        list_for_each_entry_rcu(mod, &modules, list) {
2793                if (symnum < mod->num_symtab) {
2794                        *value = mod->symtab[symnum].st_value;
2795                        *type = mod->symtab[symnum].st_info;
2796                        strlcpy(name, mod->strtab + mod->symtab[symnum].st_name,
2797                                KSYM_NAME_LEN);
2798                        strlcpy(module_name, mod->name, MODULE_NAME_LEN);
2799                        *exported = is_exported(name, *value, mod);
2800                        preempt_enable();
2801                        return 0;
2802                }
2803                symnum -= mod->num_symtab;
2804        }
2805        preempt_enable();
2806        return -ERANGE;
2807}
2808
2809static unsigned long mod_find_symname(struct module *mod, const char *name)
2810{
2811        unsigned int i;
2812
2813        for (i = 0; i < mod->num_symtab; i++)
2814                if (strcmp(name, mod->strtab+mod->symtab[i].st_name) == 0 &&
2815                    mod->symtab[i].st_info != 'U')
2816                        return mod->symtab[i].st_value;
2817        return 0;
2818}
2819
2820/* Look for this name: can be of form module:name. */
2821unsigned long module_kallsyms_lookup_name(const char *name)
2822{
2823        struct module *mod;
2824        char *colon;
2825        unsigned long ret = 0;
2826
2827        /* Don't lock: we're in enough trouble already. */
2828        preempt_disable();
2829        if ((colon = strchr(name, ':')) != NULL) {
2830                *colon = '\0';
2831                if ((mod = find_module(name)) != NULL)
2832                        ret = mod_find_symname(mod, colon+1);
2833                *colon = ':';
2834        } else {
2835                list_for_each_entry_rcu(mod, &modules, list)
2836                        if ((ret = mod_find_symname(mod, name)) != 0)
2837                                break;
2838        }
2839        preempt_enable();
2840        return ret;
2841}
2842
2843int module_kallsyms_on_each_symbol(int (*fn)(void *, const char *,
2844                                             struct module *, unsigned long),
2845                                   void *data)
2846{
2847        struct module *mod;
2848        unsigned int i;
2849        int ret;
2850
2851        list_for_each_entry(mod, &modules, list) {
2852                for (i = 0; i < mod->num_symtab; i++) {
2853                        ret = fn(data, mod->strtab + mod->symtab[i].st_name,
2854                                 mod, mod->symtab[i].st_value);
2855                        if (ret != 0)
2856                                return ret;
2857                }
2858        }
2859        return 0;
2860}
2861#endif /* CONFIG_KALLSYMS */
2862
2863static char *module_flags(struct module *mod, char *buf)
2864{
2865        int bx = 0;
2866
2867        if (mod->taints ||
2868            mod->state == MODULE_STATE_GOING ||
2869            mod->state == MODULE_STATE_COMING) {
2870                buf[bx++] = '(';
2871                if (mod->taints & (1 << TAINT_PROPRIETARY_MODULE))
2872                        buf[bx++] = 'P';
2873                if (mod->taints & (1 << TAINT_FORCED_MODULE))
2874                        buf[bx++] = 'F';
2875                if (mod->taints & (1 << TAINT_CRAP))
2876                        buf[bx++] = 'C';
2877                /*
2878                 * TAINT_FORCED_RMMOD: could be added.
2879                 * TAINT_UNSAFE_SMP, TAINT_MACHINE_CHECK, TAINT_BAD_PAGE don't
2880                 * apply to modules.
2881                 */
2882
2883                /* Show a - for module-is-being-unloaded */
2884                if (mod->state == MODULE_STATE_GOING)
2885                        buf[bx++] = '-';
2886                /* Show a + for module-is-being-loaded */
2887                if (mod->state == MODULE_STATE_COMING)
2888                        buf[bx++] = '+';
2889                buf[bx++] = ')';
2890        }
2891        buf[bx] = '\0';
2892
2893        return buf;
2894}
2895
2896#ifdef CONFIG_PROC_FS
2897/* Called by the /proc file system to return a list of modules. */
2898static void *m_start(struct seq_file *m, loff_t *pos)
2899{
2900        mutex_lock(&module_mutex);
2901        return seq_list_start(&modules, *pos);
2902}
2903
2904static void *m_next(struct seq_file *m, void *p, loff_t *pos)
2905{
2906        return seq_list_next(p, &modules, pos);
2907}
2908
2909static void m_stop(struct seq_file *m, void *p)
2910{
2911        mutex_unlock(&module_mutex);
2912}
2913
2914static int m_show(struct seq_file *m, void *p)
2915{
2916        struct module *mod = list_entry(p, struct module, list);
2917        char buf[8];
2918
2919        seq_printf(m, "%s %u",
2920                   mod->name, mod->init_size + mod->core_size);
2921        print_unload_info(m, mod);
2922
2923        /* Informative for users. */
2924        seq_printf(m, " %s",
2925                   mod->state == MODULE_STATE_GOING ? "Unloading":
2926                   mod->state == MODULE_STATE_COMING ? "Loading":
2927                   "Live");
2928        /* Used by oprofile and other similar tools. */
2929        seq_printf(m, " 0x%p", mod->module_core);
2930
2931        /* Taints info */
2932        if (mod->taints)
2933                seq_printf(m, " %s", module_flags(mod, buf));
2934
2935        seq_printf(m, "\n");
2936        return 0;
2937}
2938
2939/* Format: modulename size refcount deps address
2940
2941   Where refcount is a number or -, and deps is a comma-separated list
2942   of depends or -.
2943*/
2944static const struct seq_operations modules_op = {
2945        .start  = m_start,
2946        .next   = m_next,
2947        .stop   = m_stop,
2948        .show   = m_show
2949};
2950
2951static int modules_open(struct inode *inode, struct file *file)
2952{
2953        return seq_open(file, &modules_op);
2954}
2955
2956static const struct file_operations proc_modules_operations = {
2957        .open           = modules_open,
2958        .read           = seq_read,
2959        .llseek         = seq_lseek,
2960        .release        = seq_release,
2961};
2962
2963static int __init proc_modules_init(void)
2964{
2965        proc_create("modules", 0, NULL, &proc_modules_operations);
2966        return 0;
2967}
2968module_init(proc_modules_init);
2969#endif
2970
2971/* Given an address, look for it in the module exception tables. */
2972const struct exception_table_entry *search_module_extables(unsigned long addr)
2973{
2974        const struct exception_table_entry *e = NULL;
2975        struct module *mod;
2976
2977        preempt_disable();
2978        list_for_each_entry_rcu(mod, &modules, list) {
2979                if (mod->num_exentries == 0)
2980                        continue;
2981
2982                e = search_extable(mod->extable,
2983                                   mod->extable + mod->num_exentries - 1,
2984                                   addr);
2985                if (e)
2986                        break;
2987        }
2988        preempt_enable();
2989
2990        /* Now, if we found one, we are running inside it now, hence
2991           we cannot unload the module, hence no refcnt needed. */
2992        return e;
2993}
2994
2995/*
2996 * is_module_address - is this address inside a module?
2997 * @addr: the address to check.
2998 *
2999 * See is_module_text_address() if you simply want to see if the address
3000 * is code (not data).
3001 */
3002bool is_module_address(unsigned long addr)
3003{
3004        bool ret;
3005
3006        preempt_disable();
3007        ret = __module_address(addr) != NULL;
3008        preempt_enable();
3009
3010        return ret;
3011}
3012
3013/*
3014 * __module_address - get the module which contains an address.
3015 * @addr: the address.
3016 *
3017 * Must be called with preempt disabled or module mutex held so that
3018 * module doesn't get freed during this.
3019 */
3020struct module *__module_address(unsigned long addr)
3021{
3022        struct module *mod;
3023
3024        if (addr < module_addr_min || addr > module_addr_max)
3025                return NULL;
3026
3027        list_for_each_entry_rcu(mod, &modules, list)
3028                if (within_module_core(addr, mod)
3029                    || within_module_init(addr, mod))
3030                        return mod;
3031        return NULL;
3032}
3033EXPORT_SYMBOL_GPL(__module_address);
3034
3035/*
3036 * is_module_text_address - is this address inside module code?
3037 * @addr: the address to check.
3038 *
3039 * See is_module_address() if you simply want to see if the address is
3040 * anywhere in a module.  See kernel_text_address() for testing if an
3041 * address corresponds to kernel or module code.
3042 */
3043bool is_module_text_address(unsigned long addr)
3044{
3045        bool ret;
3046
3047        preempt_disable();
3048        ret = __module_text_address(addr) != NULL;
3049        preempt_enable();
3050
3051        return ret;
3052}
3053
3054/*
3055 * __module_text_address - get the module whose code contains an address.
3056 * @addr: the address.
3057 *
3058 * Must be called with preempt disabled or module mutex held so that
3059 * module doesn't get freed during this.
3060 */
3061struct module *__module_text_address(unsigned long addr)
3062{
3063        struct module *mod = __module_address(addr);
3064        if (mod) {
3065                /* Make sure it's within the text section. */
3066                if (!within(addr, mod->module_init, mod->init_text_size)
3067                    && !within(addr, mod->module_core, mod->core_text_size))
3068                        mod = NULL;
3069        }
3070        return mod;
3071}
3072EXPORT_SYMBOL_GPL(__module_text_address);
3073
3074/* Don't grab lock, we're oopsing. */
3075void print_modules(void)
3076{
3077        struct module *mod;
3078        char buf[8];
3079
3080        printk(KERN_DEFAULT "Modules linked in:");
3081        /* Most callers should already have preempt disabled, but make sure */
3082        preempt_disable();
3083        list_for_each_entry_rcu(mod, &modules, list)
3084                printk(" %s%s", mod->name, module_flags(mod, buf));
3085        preempt_enable();
3086        if (last_unloaded_module[0])
3087                printk(" [last unloaded: %s]", last_unloaded_module);
3088        printk("\n");
3089}
3090
3091#ifdef CONFIG_MODVERSIONS
3092/* Generate the signature for all relevant module structures here.
3093 * If these change, we don't want to try to parse the module. */
3094void module_layout(struct module *mod,
3095                   struct modversion_info *ver,
3096                   struct kernel_param *kp,
3097                   struct kernel_symbol *ks,
3098                   struct tracepoint *tp)
3099{
3100}
3101EXPORT_SYMBOL(module_layout);
3102#endif
3103
3104#ifdef CONFIG_TRACEPOINTS
3105void module_update_tracepoints(void)
3106{
3107        struct module *mod;
3108
3109        mutex_lock(&module_mutex);
3110        list_for_each_entry(mod, &modules, list)
3111                if (!mod->taints)
3112                        tracepoint_update_probe_range(mod->tracepoints,
3113                                mod->tracepoints + mod->num_tracepoints);
3114        mutex_unlock(&module_mutex);
3115}
3116
3117/*
3118 * Returns 0 if current not found.
3119 * Returns 1 if current found.
3120 */
3121int module_get_iter_tracepoints(struct tracepoint_iter *iter)
3122{
3123        struct module *iter_mod;
3124        int found = 0;
3125
3126        mutex_lock(&module_mutex);
3127        list_for_each_entry(iter_mod, &modules, list) {
3128                if (!iter_mod->taints) {
3129                        /*
3130                         * Sorted module list
3131                         */
3132                        if (iter_mod < iter->module)
3133                                continue;
3134                        else if (iter_mod > iter->module)
3135                                iter->tracepoint = NULL;
3136                        found = tracepoint_get_iter_range(&iter->tracepoint,
3137                                iter_mod->tracepoints,
3138                                iter_mod->tracepoints
3139                                        + iter_mod->num_tracepoints);
3140                        if (found) {
3141                                iter->module = iter_mod;
3142                                break;
3143                        }
3144                }
3145        }
3146        mutex_unlock(&module_mutex);
3147        return found;
3148}
3149#endif
3150