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authorLinus Torvalds2013-01-20 18:44:28 -0600
committerLinus Torvalds2013-01-20 18:44:28 -0600
commit226364766f936d249e408de03821468c1bf11dda (patch)
tree3b4feabb40a87f311ae92bb973c18293d05597e8 /kernel
parent3a142ed962958d3063f648738a3384ab90017100 (diff)
parent1fb9341ac34825aa40354e74d9a2c69df7d2c304 (diff)
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Merge tag 'fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux
Pull module fixes and a virtio block fix from Rusty Russell: "Various minor fixes, but a slightly more complex one to fix the per-cpu overload problem introduced recently by kvm id changes." * tag 'fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux: module: put modules in list much earlier. module: add new state MODULE_STATE_UNFORMED. module: prevent warning when finit_module a 0 sized file virtio-blk: Don't free ida when disk is in use
Diffstat (limited to 'kernel')
-rw-r--r--kernel/debug/kdb/kdb_main.c2
-rw-r--r--kernel/module.c154
2 files changed, 110 insertions, 46 deletions
diff --git a/kernel/debug/kdb/kdb_main.c b/kernel/debug/kdb/kdb_main.c
index 4d5f8d5612f..8875254120b 100644
--- a/kernel/debug/kdb/kdb_main.c
+++ b/kernel/debug/kdb/kdb_main.c
@@ -1970,6 +1970,8 @@ static int kdb_lsmod(int argc, const char **argv)
1970 1970
1971 kdb_printf("Module Size modstruct Used by\n"); 1971 kdb_printf("Module Size modstruct Used by\n");
1972 list_for_each_entry(mod, kdb_modules, list) { 1972 list_for_each_entry(mod, kdb_modules, list) {
1973 if (mod->state == MODULE_STATE_UNFORMED)
1974 continue;
1973 1975
1974 kdb_printf("%-20s%8u 0x%p ", mod->name, 1976 kdb_printf("%-20s%8u 0x%p ", mod->name,
1975 mod->core_size, (void *)mod); 1977 mod->core_size, (void *)mod);
diff --git a/kernel/module.c b/kernel/module.c
index b10b048367e..d25e359279a 100644
--- a/kernel/module.c
+++ b/kernel/module.c
@@ -188,6 +188,7 @@ struct load_info {
188 ongoing or failed initialization etc. */ 188 ongoing or failed initialization etc. */
189static inline int strong_try_module_get(struct module *mod) 189static inline int strong_try_module_get(struct module *mod)
190{ 190{
191 BUG_ON(mod && mod->state == MODULE_STATE_UNFORMED);
191 if (mod && mod->state == MODULE_STATE_COMING) 192 if (mod && mod->state == MODULE_STATE_COMING)
192 return -EBUSY; 193 return -EBUSY;
193 if (try_module_get(mod)) 194 if (try_module_get(mod))
@@ -343,6 +344,9 @@ bool each_symbol_section(bool (*fn)(const struct symsearch *arr,
343#endif 344#endif
344 }; 345 };
345 346
347 if (mod->state == MODULE_STATE_UNFORMED)
348 continue;
349
346 if (each_symbol_in_section(arr, ARRAY_SIZE(arr), mod, fn, data)) 350 if (each_symbol_in_section(arr, ARRAY_SIZE(arr), mod, fn, data))
347 return true; 351 return true;
348 } 352 }
@@ -450,16 +454,24 @@ const struct kernel_symbol *find_symbol(const char *name,
450EXPORT_SYMBOL_GPL(find_symbol); 454EXPORT_SYMBOL_GPL(find_symbol);
451 455
452/* Search for module by name: must hold module_mutex. */ 456/* Search for module by name: must hold module_mutex. */
453struct module *find_module(const char *name) 457static struct module *find_module_all(const char *name,
458 bool even_unformed)
454{ 459{
455 struct module *mod; 460 struct module *mod;
456 461
457 list_for_each_entry(mod, &modules, list) { 462 list_for_each_entry(mod, &modules, list) {
463 if (!even_unformed && mod->state == MODULE_STATE_UNFORMED)
464 continue;
458 if (strcmp(mod->name, name) == 0) 465 if (strcmp(mod->name, name) == 0)
459 return mod; 466 return mod;
460 } 467 }
461 return NULL; 468 return NULL;
462} 469}
470
471struct module *find_module(const char *name)
472{
473 return find_module_all(name, false);
474}
463EXPORT_SYMBOL_GPL(find_module); 475EXPORT_SYMBOL_GPL(find_module);
464 476
465#ifdef CONFIG_SMP 477#ifdef CONFIG_SMP
@@ -525,6 +537,8 @@ bool is_module_percpu_address(unsigned long addr)
525 preempt_disable(); 537 preempt_disable();
526 538
527 list_for_each_entry_rcu(mod, &modules, list) { 539 list_for_each_entry_rcu(mod, &modules, list) {
540 if (mod->state == MODULE_STATE_UNFORMED)
541 continue;
528 if (!mod->percpu_size) 542 if (!mod->percpu_size)
529 continue; 543 continue;
530 for_each_possible_cpu(cpu) { 544 for_each_possible_cpu(cpu) {
@@ -1048,6 +1062,8 @@ static ssize_t show_initstate(struct module_attribute *mattr,
1048 case MODULE_STATE_GOING: 1062 case MODULE_STATE_GOING:
1049 state = "going"; 1063 state = "going";
1050 break; 1064 break;
1065 default:
1066 BUG();
1051 } 1067 }
1052 return sprintf(buffer, "%s\n", state); 1068 return sprintf(buffer, "%s\n", state);
1053} 1069}
@@ -1786,6 +1802,8 @@ void set_all_modules_text_rw(void)
1786 1802
1787 mutex_lock(&module_mutex); 1803 mutex_lock(&module_mutex);
1788 list_for_each_entry_rcu(mod, &modules, list) { 1804 list_for_each_entry_rcu(mod, &modules, list) {
1805 if (mod->state == MODULE_STATE_UNFORMED)
1806 continue;
1789 if ((mod->module_core) && (mod->core_text_size)) { 1807 if ((mod->module_core) && (mod->core_text_size)) {
1790 set_page_attributes(mod->module_core, 1808 set_page_attributes(mod->module_core,
1791 mod->module_core + mod->core_text_size, 1809 mod->module_core + mod->core_text_size,
@@ -1807,6 +1825,8 @@ void set_all_modules_text_ro(void)
1807 1825
1808 mutex_lock(&module_mutex); 1826 mutex_lock(&module_mutex);
1809 list_for_each_entry_rcu(mod, &modules, list) { 1827 list_for_each_entry_rcu(mod, &modules, list) {
1828 if (mod->state == MODULE_STATE_UNFORMED)
1829 continue;
1810 if ((mod->module_core) && (mod->core_text_size)) { 1830 if ((mod->module_core) && (mod->core_text_size)) {
1811 set_page_attributes(mod->module_core, 1831 set_page_attributes(mod->module_core,
1812 mod->module_core + mod->core_text_size, 1832 mod->module_core + mod->core_text_size,
@@ -2527,6 +2547,13 @@ static int copy_module_from_fd(int fd, struct load_info *info)
2527 err = -EFBIG; 2547 err = -EFBIG;
2528 goto out; 2548 goto out;
2529 } 2549 }
2550
2551 /* Don't hand 0 to vmalloc, it whines. */
2552 if (stat.size == 0) {
2553 err = -EINVAL;
2554 goto out;
2555 }
2556
2530 info->hdr = vmalloc(stat.size); 2557 info->hdr = vmalloc(stat.size);
2531 if (!info->hdr) { 2558 if (!info->hdr) {
2532 err = -ENOMEM; 2559 err = -ENOMEM;
@@ -2990,8 +3017,9 @@ static bool finished_loading(const char *name)
2990 bool ret; 3017 bool ret;
2991 3018
2992 mutex_lock(&module_mutex); 3019 mutex_lock(&module_mutex);
2993 mod = find_module(name); 3020 mod = find_module_all(name, true);
2994 ret = !mod || mod->state != MODULE_STATE_COMING; 3021 ret = !mod || mod->state == MODULE_STATE_LIVE
3022 || mod->state == MODULE_STATE_GOING;
2995 mutex_unlock(&module_mutex); 3023 mutex_unlock(&module_mutex);
2996 3024
2997 return ret; 3025 return ret;
@@ -3136,6 +3164,32 @@ static int load_module(struct load_info *info, const char __user *uargs,
3136 goto free_copy; 3164 goto free_copy;
3137 } 3165 }
3138 3166
3167 /*
3168 * We try to place it in the list now to make sure it's unique
3169 * before we dedicate too many resources. In particular,
3170 * temporary percpu memory exhaustion.
3171 */
3172 mod->state = MODULE_STATE_UNFORMED;
3173again:
3174 mutex_lock(&module_mutex);
3175 if ((old = find_module_all(mod->name, true)) != NULL) {
3176 if (old->state == MODULE_STATE_COMING
3177 || old->state == MODULE_STATE_UNFORMED) {
3178 /* Wait in case it fails to load. */
3179 mutex_unlock(&module_mutex);
3180 err = wait_event_interruptible(module_wq,
3181 finished_loading(mod->name));
3182 if (err)
3183 goto free_module;
3184 goto again;
3185 }
3186 err = -EEXIST;
3187 mutex_unlock(&module_mutex);
3188 goto free_module;
3189 }
3190 list_add_rcu(&mod->list, &modules);
3191 mutex_unlock(&module_mutex);
3192
3139#ifdef CONFIG_MODULE_SIG 3193#ifdef CONFIG_MODULE_SIG
3140 mod->sig_ok = info->sig_ok; 3194 mod->sig_ok = info->sig_ok;
3141 if (!mod->sig_ok) 3195 if (!mod->sig_ok)
@@ -3145,7 +3199,7 @@ static int load_module(struct load_info *info, const char __user *uargs,
3145 /* Now module is in final location, initialize linked lists, etc. */ 3199 /* Now module is in final location, initialize linked lists, etc. */
3146 err = module_unload_init(mod); 3200 err = module_unload_init(mod);
3147 if (err) 3201 if (err)
3148 goto free_module; 3202 goto unlink_mod;
3149 3203
3150 /* Now we've got everything in the final locations, we can 3204 /* Now we've got everything in the final locations, we can
3151 * find optional sections. */ 3205 * find optional sections. */
@@ -3180,54 +3234,33 @@ static int load_module(struct load_info *info, const char __user *uargs,
3180 goto free_arch_cleanup; 3234 goto free_arch_cleanup;
3181 } 3235 }
3182 3236
3183 /* Mark state as coming so strong_try_module_get() ignores us. */
3184 mod->state = MODULE_STATE_COMING;
3185
3186 /* Now sew it into the lists so we can get lockdep and oops
3187 * info during argument parsing. No one should access us, since
3188 * strong_try_module_get() will fail.
3189 * lockdep/oops can run asynchronous, so use the RCU list insertion
3190 * function to insert in a way safe to concurrent readers.
3191 * The mutex protects against concurrent writers.
3192 */
3193again:
3194 mutex_lock(&module_mutex);
3195 if ((old = find_module(mod->name)) != NULL) {
3196 if (old->state == MODULE_STATE_COMING) {
3197 /* Wait in case it fails to load. */
3198 mutex_unlock(&module_mutex);
3199 err = wait_event_interruptible(module_wq,
3200 finished_loading(mod->name));
3201 if (err)
3202 goto free_arch_cleanup;
3203 goto again;
3204 }
3205 err = -EEXIST;
3206 goto unlock;
3207 }
3208
3209 /* This has to be done once we're sure module name is unique. */
3210 dynamic_debug_setup(info->debug, info->num_debug); 3237 dynamic_debug_setup(info->debug, info->num_debug);
3211 3238
3212 /* Find duplicate symbols */ 3239 mutex_lock(&module_mutex);
3240 /* Find duplicate symbols (must be called under lock). */
3213 err = verify_export_symbols(mod); 3241 err = verify_export_symbols(mod);
3214 if (err < 0) 3242 if (err < 0)
3215 goto ddebug; 3243 goto ddebug_cleanup;
3216 3244
3245 /* This relies on module_mutex for list integrity. */
3217 module_bug_finalize(info->hdr, info->sechdrs, mod); 3246 module_bug_finalize(info->hdr, info->sechdrs, mod);
3218 list_add_rcu(&mod->list, &modules); 3247
3248 /* Mark state as coming so strong_try_module_get() ignores us,
3249 * but kallsyms etc. can see us. */
3250 mod->state = MODULE_STATE_COMING;
3251
3219 mutex_unlock(&module_mutex); 3252 mutex_unlock(&module_mutex);
3220 3253
3221 /* Module is ready to execute: parsing args may do that. */ 3254 /* Module is ready to execute: parsing args may do that. */
3222 err = parse_args(mod->name, mod->args, mod->kp, mod->num_kp, 3255 err = parse_args(mod->name, mod->args, mod->kp, mod->num_kp,
3223 -32768, 32767, &ddebug_dyndbg_module_param_cb); 3256 -32768, 32767, &ddebug_dyndbg_module_param_cb);
3224 if (err < 0) 3257 if (err < 0)
3225 goto unlink; 3258 goto bug_cleanup;
3226 3259
3227 /* Link in to syfs. */ 3260 /* Link in to syfs. */
3228 err = mod_sysfs_setup(mod, info, mod->kp, mod->num_kp); 3261 err = mod_sysfs_setup(mod, info, mod->kp, mod->num_kp);
3229 if (err < 0) 3262 if (err < 0)
3230 goto unlink; 3263 goto bug_cleanup;
3231 3264
3232 /* Get rid of temporary copy. */ 3265 /* Get rid of temporary copy. */
3233 free_copy(info); 3266 free_copy(info);
@@ -3237,16 +3270,13 @@ again:
3237 3270
3238 return do_init_module(mod); 3271 return do_init_module(mod);
3239 3272
3240 unlink: 3273 bug_cleanup:
3274 /* module_bug_cleanup needs module_mutex protection */
3241 mutex_lock(&module_mutex); 3275 mutex_lock(&module_mutex);
3242 /* Unlink carefully: kallsyms could be walking list. */
3243 list_del_rcu(&mod->list);
3244 module_bug_cleanup(mod); 3276 module_bug_cleanup(mod);
3245 wake_up_all(&module_wq);
3246 ddebug:
3247 dynamic_debug_remove(info->debug);
3248 unlock:
3249 mutex_unlock(&module_mutex); 3277 mutex_unlock(&module_mutex);
3278 ddebug_cleanup:
3279 dynamic_debug_remove(info->debug);
3250 synchronize_sched(); 3280 synchronize_sched();
3251 kfree(mod->args); 3281 kfree(mod->args);
3252 free_arch_cleanup: 3282 free_arch_cleanup:
@@ -3255,6 +3285,12 @@ again:
3255 free_modinfo(mod); 3285 free_modinfo(mod);
3256 free_unload: 3286 free_unload:
3257 module_unload_free(mod); 3287 module_unload_free(mod);
3288 unlink_mod:
3289 mutex_lock(&module_mutex);
3290 /* Unlink carefully: kallsyms could be walking list. */
3291 list_del_rcu(&mod->list);
3292 wake_up_all(&module_wq);
3293 mutex_unlock(&module_mutex);
3258 free_module: 3294 free_module:
3259 module_deallocate(mod, info); 3295 module_deallocate(mod, info);
3260 free_copy: 3296 free_copy:
@@ -3377,6 +3413,8 @@ const char *module_address_lookup(unsigned long addr,
3377 3413
3378 preempt_disable(); 3414 preempt_disable();
3379 list_for_each_entry_rcu(mod, &modules, list) { 3415 list_for_each_entry_rcu(mod, &modules, list) {
3416 if (mod->state == MODULE_STATE_UNFORMED)
3417 continue;
3380 if (within_module_init(addr, mod) || 3418 if (within_module_init(addr, mod) ||
3381 within_module_core(addr, mod)) { 3419 within_module_core(addr, mod)) {
3382 if (modname) 3420 if (modname)
@@ -3400,6 +3438,8 @@ int lookup_module_symbol_name(unsigned long addr, char *symname)
3400 3438
3401 preempt_disable(); 3439 preempt_disable();
3402 list_for_each_entry_rcu(mod, &modules, list) { 3440 list_for_each_entry_rcu(mod, &modules, list) {
3441 if (mod->state == MODULE_STATE_UNFORMED)
3442 continue;
3403 if (within_module_init(addr, mod) || 3443 if (within_module_init(addr, mod) ||
3404 within_module_core(addr, mod)) { 3444 within_module_core(addr, mod)) {
3405 const char *sym; 3445 const char *sym;
@@ -3424,6 +3464,8 @@ int lookup_module_symbol_attrs(unsigned long addr, unsigned long *size,
3424 3464
3425 preempt_disable(); 3465 preempt_disable();
3426 list_for_each_entry_rcu(mod, &modules, list) { 3466 list_for_each_entry_rcu(mod, &modules, list) {
3467 if (mod->state == MODULE_STATE_UNFORMED)
3468 continue;
3427 if (within_module_init(addr, mod) || 3469 if (within_module_init(addr, mod) ||
3428 within_module_core(addr, mod)) { 3470 within_module_core(addr, mod)) {
3429 const char *sym; 3471 const char *sym;
@@ -3451,6 +3493,8 @@ int module_get_kallsym(unsigned int symnum, unsigned long *value, char *type,
3451 3493
3452 preempt_disable(); 3494 preempt_disable();
3453 list_for_each_entry_rcu(mod, &modules, list) { 3495 list_for_each_entry_rcu(mod, &modules, list) {
3496 if (mod->state == MODULE_STATE_UNFORMED)
3497 continue;
3454 if (symnum < mod->num_symtab) { 3498 if (symnum < mod->num_symtab) {
3455 *value = mod->symtab[symnum].st_value; 3499 *value = mod->symtab[symnum].st_value;
3456 *type = mod->symtab[symnum].st_info; 3500 *type = mod->symtab[symnum].st_info;
@@ -3493,9 +3537,12 @@ unsigned long module_kallsyms_lookup_name(const char *name)
3493 ret = mod_find_symname(mod, colon+1); 3537 ret = mod_find_symname(mod, colon+1);
3494 *colon = ':'; 3538 *colon = ':';
3495 } else { 3539 } else {
3496 list_for_each_entry_rcu(mod, &modules, list) 3540 list_for_each_entry_rcu(mod, &modules, list) {
3541 if (mod->state == MODULE_STATE_UNFORMED)
3542 continue;
3497 if ((ret = mod_find_symname(mod, name)) != 0) 3543 if ((ret = mod_find_symname(mod, name)) != 0)
3498 break; 3544 break;
3545 }
3499 } 3546 }
3500 preempt_enable(); 3547 preempt_enable();
3501 return ret; 3548 return ret;
@@ -3510,6 +3557,8 @@ int module_kallsyms_on_each_symbol(int (*fn)(void *, const char *,
3510 int ret; 3557 int ret;
3511 3558
3512 list_for_each_entry(mod, &modules, list) { 3559 list_for_each_entry(mod, &modules, list) {
3560 if (mod->state == MODULE_STATE_UNFORMED)
3561 continue;
3513 for (i = 0; i < mod->num_symtab; i++) { 3562 for (i = 0; i < mod->num_symtab; i++) {
3514 ret = fn(data, mod->strtab + mod->symtab[i].st_name, 3563 ret = fn(data, mod->strtab + mod->symtab[i].st_name,
3515 mod, mod->symtab[i].st_value); 3564 mod, mod->symtab[i].st_value);
@@ -3525,6 +3574,7 @@ static char *module_flags(struct module *mod, char *buf)
3525{ 3574{
3526 int bx = 0; 3575 int bx = 0;
3527 3576
3577 BUG_ON(mod->state == MODULE_STATE_UNFORMED);
3528 if (mod->taints || 3578 if (mod->taints ||
3529 mod->state == MODULE_STATE_GOING || 3579 mod->state == MODULE_STATE_GOING ||
3530 mod->state == MODULE_STATE_COMING) { 3580 mod->state == MODULE_STATE_COMING) {
@@ -3566,6 +3616,10 @@ static int m_show(struct seq_file *m, void *p)
3566 struct module *mod = list_entry(p, struct module, list); 3616 struct module *mod = list_entry(p, struct module, list);
3567 char buf[8]; 3617 char buf[8];
3568 3618
3619 /* We always ignore unformed modules. */
3620 if (mod->state == MODULE_STATE_UNFORMED)
3621 return 0;
3622
3569 seq_printf(m, "%s %u", 3623 seq_printf(m, "%s %u",
3570 mod->name, mod->init_size + mod->core_size); 3624 mod->name, mod->init_size + mod->core_size);
3571 print_unload_info(m, mod); 3625 print_unload_info(m, mod);
@@ -3626,6 +3680,8 @@ const struct exception_table_entry *search_module_extables(unsigned long addr)
3626 3680
3627 preempt_disable(); 3681 preempt_disable();
3628 list_for_each_entry_rcu(mod, &modules, list) { 3682 list_for_each_entry_rcu(mod, &modules, list) {
3683 if (mod->state == MODULE_STATE_UNFORMED)
3684 continue;
3629 if (mod->num_exentries == 0) 3685 if (mod->num_exentries == 0)
3630 continue; 3686 continue;
3631 3687
@@ -3674,10 +3730,13 @@ struct module *__module_address(unsigned long addr)
3674 if (addr < module_addr_min || addr > module_addr_max) 3730 if (addr < module_addr_min || addr > module_addr_max)
3675 return NULL; 3731 return NULL;
3676 3732
3677 list_for_each_entry_rcu(mod, &modules, list) 3733 list_for_each_entry_rcu(mod, &modules, list) {
3734 if (mod->state == MODULE_STATE_UNFORMED)
3735 continue;
3678 if (within_module_core(addr, mod) 3736 if (within_module_core(addr, mod)
3679 || within_module_init(addr, mod)) 3737 || within_module_init(addr, mod))
3680 return mod; 3738 return mod;
3739 }
3681 return NULL; 3740 return NULL;
3682} 3741}
3683EXPORT_SYMBOL_GPL(__module_address); 3742EXPORT_SYMBOL_GPL(__module_address);
@@ -3730,8 +3789,11 @@ void print_modules(void)
3730 printk(KERN_DEFAULT "Modules linked in:"); 3789 printk(KERN_DEFAULT "Modules linked in:");
3731 /* Most callers should already have preempt disabled, but make sure */ 3790 /* Most callers should already have preempt disabled, but make sure */
3732 preempt_disable(); 3791 preempt_disable();
3733 list_for_each_entry_rcu(mod, &modules, list) 3792 list_for_each_entry_rcu(mod, &modules, list) {
3793 if (mod->state == MODULE_STATE_UNFORMED)
3794 continue;
3734 printk(" %s%s", mod->name, module_flags(mod, buf)); 3795 printk(" %s%s", mod->name, module_flags(mod, buf));
3796 }
3735 preempt_enable(); 3797 preempt_enable();
3736 if (last_unloaded_module[0]) 3798 if (last_unloaded_module[0])
3737 printk(" [last unloaded: %s]", last_unloaded_module); 3799 printk(" [last unloaded: %s]", last_unloaded_module);