X-Git-Url: http://ftp.safe.ca/?a=blobdiff_plain;f=kernel%2Fmodule.c;h=901cd6ac2f11d9d4b54d3bff34e10495e86f01a2;hb=a4573c488dd531c6e2d308ce8a7413c4a2646207;hp=0ae811785c59dba901eb52d6476113a6e44e4789;hpb=97c146ef075dc40ae34407c03d3860fc3850b8e8;p=safe%2Fjmp%2Flinux-2.6 diff --git a/kernel/module.c b/kernel/module.c index 0ae8117..901cd6a 100644 --- a/kernel/module.c +++ b/kernel/module.c @@ -46,6 +46,7 @@ #include #include #include +#include #if 0 #define DEBUGP printk @@ -65,6 +66,9 @@ static DEFINE_MUTEX(module_mutex); static LIST_HEAD(modules); +/* Waiting for a module to finish initializing? */ +static DECLARE_WAIT_QUEUE_HEAD(module_wq); + static BLOCKING_NOTIFIER_HEAD(module_notify_list); int register_module_notifier(struct notifier_block * nb) @@ -84,8 +88,11 @@ EXPORT_SYMBOL(unregister_module_notifier); static inline int strong_try_module_get(struct module *mod) { if (mod && mod->state == MODULE_STATE_COMING) + return -EBUSY; + if (try_module_get(mod)) return 0; - return try_module_get(mod); + else + return -ENOENT; } static inline void add_taint_module(struct module *mod, unsigned flag) @@ -284,7 +291,7 @@ static unsigned long __find_symbol(const char *name, } } DEBUGP("Failed to find symbol %s\n", name); - return 0; + return -ENOENT; } /* Search for module by name: must hold module_mutex. */ @@ -337,9 +344,6 @@ static inline unsigned int block_size(int val) return val; } -/* Created by linker magic */ -extern char __per_cpu_start[], __per_cpu_end[]; - static void *percpu_modalloc(unsigned long size, unsigned long align, const char *name) { @@ -424,6 +428,14 @@ static unsigned int find_pcpusec(Elf_Ehdr *hdr, return find_sec(hdr, sechdrs, secstrings, ".data.percpu"); } +static void percpu_modcopy(void *pcpudest, const void *from, unsigned long size) +{ + int cpu; + + for_each_possible_cpu(cpu) + memcpy(pcpudest + per_cpu_offset(cpu), from, size); +} + static int percpu_modinit(void) { pcpu_num_used = 2; @@ -496,6 +508,8 @@ static struct module_attribute modinfo_##field = { \ MODINFO_ATTR(version); MODINFO_ATTR(srcversion); +static char last_unloaded_module[MODULE_NAME_LEN+1]; + #ifdef CONFIG_MODULE_UNLOAD /* Init the unload section of the module. */ static void module_unload_init(struct module *mod) @@ -537,11 +551,21 @@ static int already_uses(struct module *a, struct module *b) static int use_module(struct module *a, struct module *b) { struct module_use *use; - int no_warn; + int no_warn, err; if (b == NULL || already_uses(a, b)) return 1; - if (!strong_try_module_get(b)) + /* If we're interrupted or time out, we fail. */ + if (wait_event_interruptible_timeout( + module_wq, (err = strong_try_module_get(b)) != -EBUSY, + 30 * HZ) <= 0) { + printk("%s: gave up waiting for init of module %s.\n", + a->name, b->name); + return 0; + } + + /* If strong_try_module_get() returned a different error, we fail. */ + if (err) return 0; DEBUGP("Allocating new usage for %s.\n", a->name); @@ -719,6 +743,8 @@ sys_delete_module(const char __user *name_user, unsigned int flags) mod->exit(); mutex_lock(&module_mutex); } + /* Store the name of the last unloaded module for diagnostic purposes */ + strlcpy(last_unloaded_module, mod->name, sizeof(last_unloaded_module)); free_module(mod); out: @@ -755,7 +781,7 @@ void __symbol_put(const char *symbol) const unsigned long *crc; preempt_disable(); - if (!__find_symbol(symbol, &owner, &crc, 1)) + if (IS_ERR_VALUE(__find_symbol(symbol, &owner, &crc, 1))) BUG(); module_put(owner); preempt_enable(); @@ -812,7 +838,7 @@ static inline void module_unload_free(struct module *mod) static inline int use_module(struct module *a, struct module *b) { - return strong_try_module_get(b); + return strong_try_module_get(b) == 0; } static inline void module_unload_init(struct module *mod) @@ -901,7 +927,8 @@ static inline int check_modstruct_version(Elf_Shdr *sechdrs, const unsigned long *crc; struct module *owner; - if (!__find_symbol("struct_module", &owner, &crc, 1)) + if (IS_ERR_VALUE(__find_symbol("struct_module", + &owner, &crc, 1))) BUG(); return check_version(sechdrs, versindex, "struct_module", mod, crc); @@ -950,22 +977,21 @@ static unsigned long resolve_symbol(Elf_Shdr *sechdrs, ret = __find_symbol(name, &owner, &crc, !(mod->taints & TAINT_PROPRIETARY_MODULE)); - if (ret) { + if (!IS_ERR_VALUE(ret)) { /* use_module can fail due to OOM, or module initialization or unloading */ if (!check_version(sechdrs, versindex, name, mod, crc) || !use_module(mod, owner)) - ret = 0; + ret = -EINVAL; } return ret; } - /* * /sys/module/foo/sections stuff * J. Corbet */ -#ifdef CONFIG_KALLSYMS +#if defined(CONFIG_KALLSYMS) && defined(CONFIG_SYSFS) static ssize_t module_sect_show(struct module_attribute *mattr, struct module *mod, char *buf) { @@ -1161,7 +1187,7 @@ static inline void add_notes_attrs(struct module *mod, unsigned int nsect, static inline void remove_notes_attrs(struct module *mod) { } -#endif /* CONFIG_KALLSYMS */ +#endif #ifdef CONFIG_SYSFS int module_add_modinfo_attrs(struct module *mod) @@ -1204,12 +1230,11 @@ void module_remove_modinfo_attrs(struct module *mod) } kfree(mod->modinfo_attrs); } -#endif -#ifdef CONFIG_SYSFS int mod_sysfs_init(struct module *mod) { int err; + struct kobject *kobj; if (!module_sysfs_initialized) { printk(KERN_ERR "%s: module sysfs not initialized\n", @@ -1217,18 +1242,25 @@ int mod_sysfs_init(struct module *mod) err = -EINVAL; goto out; } - memset(&mod->mkobj.kobj, 0, sizeof(mod->mkobj.kobj)); - err = kobject_set_name(&mod->mkobj.kobj, "%s", mod->name); - if (err) + + kobj = kset_find_obj(module_kset, mod->name); + if (kobj) { + printk(KERN_ERR "%s: module is already loaded\n", mod->name); + kobject_put(kobj); + err = -EINVAL; goto out; - mod->mkobj.kobj.kset = module_kset; - mod->mkobj.kobj.ktype = &module_ktype; + } + mod->mkobj.mod = mod; - kobject_init(&mod->mkobj.kobj); + memset(&mod->mkobj.kobj, 0, sizeof(mod->mkobj.kobj)); + mod->mkobj.kobj.kset = module_kset; + err = kobject_init_and_add(&mod->mkobj.kobj, &module_ktype, NULL, + "%s", mod->name); + if (err) + kobject_put(&mod->mkobj.kobj); /* delay uevent until full sysfs population */ - err = kobject_add(&mod->mkobj.kobj); out: return err; } @@ -1259,9 +1291,8 @@ int mod_sysfs_setup(struct module *mod, out_unreg_param: module_param_sysfs_remove(mod); out_unreg_holders: - kobject_unregister(mod->holders_dir); + kobject_put(mod->holders_dir); out_unreg: - kobject_del(&mod->mkobj.kobj); kobject_put(&mod->mkobj.kobj); return err; } @@ -1271,9 +1302,20 @@ static void mod_kobject_remove(struct module *mod) { module_remove_modinfo_attrs(mod); module_param_sysfs_remove(mod); - kobject_unregister(mod->mkobj.drivers_dir); - kobject_unregister(mod->holders_dir); - kobject_unregister(&mod->mkobj.kobj); + kobject_put(mod->mkobj.drivers_dir); + kobject_put(mod->holders_dir); + kobject_put(&mod->mkobj.kobj); +} + +/* + * link the module with the whole machine is stopped with interrupts off + * - this defends against kallsyms not taking locks + */ +static int __link_module(void *_mod) +{ + struct module *mod = _mod; + list_add(&mod->list, &modules); + return 0; } /* @@ -1325,7 +1367,9 @@ void *__symbol_get(const char *symbol) preempt_disable(); value = __find_symbol(symbol, &owner, &crc, 1); - if (value && !strong_try_module_get(owner)) + if (IS_ERR_VALUE(value)) + value = 0; + else if (strong_try_module_get(owner)) value = 0; preempt_enable(); @@ -1345,14 +1389,16 @@ static int verify_export_symbols(struct module *mod) const unsigned long *crc; for (i = 0; i < mod->num_syms; i++) - if (__find_symbol(mod->syms[i].name, &owner, &crc, 1)) { + if (!IS_ERR_VALUE(__find_symbol(mod->syms[i].name, + &owner, &crc, 1))) { name = mod->syms[i].name; ret = -ENOEXEC; goto dup; } for (i = 0; i < mod->num_gpl_syms; i++) - if (__find_symbol(mod->gpl_syms[i].name, &owner, &crc, 1)) { + if (!IS_ERR_VALUE(__find_symbol(mod->gpl_syms[i].name, + &owner, &crc, 1))) { name = mod->gpl_syms[i].name; ret = -ENOEXEC; goto dup; @@ -1402,7 +1448,7 @@ static int simplify_symbols(Elf_Shdr *sechdrs, strtab + sym[i].st_name, mod); /* Ok if resolved. */ - if (sym[i].st_value != 0) + if (!IS_ERR_VALUE(sym[i].st_value)) break; /* Ok if weak. */ if (ELF_ST_BIND(sym[i].st_info) == STB_WEAK) @@ -1888,7 +1934,7 @@ static struct module *load_module(void __user *umod, set_license(mod, get_modinfo(sechdrs, infoindex, "license")); if (strcmp(mod->name, "ndiswrapper") == 0) - add_taint(TAINT_PROPRIETARY_MODULE); + add_taint_module(mod, TAINT_PROPRIETARY_MODULE); if (strcmp(mod->name, "driverloader") == 0) add_taint_module(mod, TAINT_PROPRIETARY_MODULE); @@ -1989,7 +2035,7 @@ static struct module *load_module(void __user *umod, #ifdef CONFIG_MARKERS if (!mod->taints) marker_update_probe_range(mod->markers, - mod->markers + mod->num_markers, NULL, NULL); + mod->markers + mod->num_markers); #endif err = module_finalize(hdr, sechdrs, mod); if (err < 0) @@ -2018,6 +2064,11 @@ static struct module *load_module(void __user *umod, printk(KERN_WARNING "%s: Ignoring obsolete parameters\n", mod->name); + /* Now sew it into the lists so we can get lockdep and oops + * info during argument parsing. Noone should access us, since + * strong_try_module_get() will fail. */ + stop_machine_run(__link_module, mod, NR_CPUS); + /* Size of section 0 is 0, so this works well if no params */ err = parse_args(mod->name, mod->args, (struct kernel_param *) @@ -2026,7 +2077,7 @@ static struct module *load_module(void __user *umod, / sizeof(struct kernel_param), NULL); if (err < 0) - goto arch_cleanup; + goto unlink; err = mod_sysfs_setup(mod, (struct kernel_param *) @@ -2034,7 +2085,7 @@ static struct module *load_module(void __user *umod, sechdrs[setupindex].sh_size / sizeof(struct kernel_param)); if (err < 0) - goto arch_cleanup; + goto unlink; add_sect_attrs(mod, hdr->e_shnum, secstrings, sechdrs); add_notes_attrs(mod, hdr->e_shnum, secstrings, sechdrs); @@ -2049,7 +2100,8 @@ static struct module *load_module(void __user *umod, /* Done! */ return mod; - arch_cleanup: + unlink: + stop_machine_run(__unlink_module, mod, NR_CPUS); module_arch_cleanup(mod); cleanup: kobject_del(&mod->mkobj.kobj); @@ -2074,17 +2126,6 @@ static struct module *load_module(void __user *umod, goto free_hdr; } -/* - * link the module with the whole machine is stopped with interrupts off - * - this defends against kallsyms not taking locks - */ -static int __link_module(void *_mod) -{ - struct module *mod = _mod; - list_add(&mod->list, &modules); - return 0; -} - /* This is where the real work happens */ asmlinkage long sys_init_module(void __user *umod, @@ -2109,10 +2150,6 @@ sys_init_module(void __user *umod, return PTR_ERR(mod); } - /* Now sew it into the lists. They won't access us, since - strong_try_module_get() will fail. */ - stop_machine_run(__link_module, mod, NR_CPUS); - /* Drop lock so they can recurse */ mutex_unlock(&module_mutex); @@ -2131,6 +2168,7 @@ sys_init_module(void __user *umod, mutex_lock(&module_mutex); free_module(mod); mutex_unlock(&module_mutex); + wake_up(&module_wq); return ret; } @@ -2145,6 +2183,7 @@ sys_init_module(void __user *umod, mod->init_size = 0; mod->init_text_size = 0; mutex_unlock(&module_mutex); + wake_up(&module_wq); return 0; } @@ -2209,14 +2248,13 @@ static const char *get_ksymbol(struct module *mod, return mod->strtab + mod->symtab[best].st_name; } -/* For kallsyms to ask for address resolution. NULL means not found. - We don't lock, as this is used for oops resolution and races are a - lesser concern. */ -/* FIXME: Risky: returns a pointer into a module w/o lock */ +/* For kallsyms to ask for address resolution. NULL means not found. Careful + * not to lock to avoid deadlock on oopses, simply disable preemption. */ const char *module_address_lookup(unsigned long addr, - unsigned long *size, - unsigned long *offset, - char **modname) + unsigned long *size, + unsigned long *offset, + char **modname, + char *namebuf) { struct module *mod; const char *ret = NULL; @@ -2231,6 +2269,11 @@ const char *module_address_lookup(unsigned long addr, break; } } + /* Make a copy in here where it's safe */ + if (ret) { + strncpy(namebuf, ret, KSYM_NAME_LEN - 1); + ret = namebuf; + } preempt_enable(); return ret; } @@ -2360,21 +2403,30 @@ static void m_stop(struct seq_file *m, void *p) mutex_unlock(&module_mutex); } -static char *taint_flags(unsigned int taints, char *buf) +static char *module_flags(struct module *mod, char *buf) { int bx = 0; - if (taints) { + if (mod->taints || + mod->state == MODULE_STATE_GOING || + mod->state == MODULE_STATE_COMING) { buf[bx++] = '('; - if (taints & TAINT_PROPRIETARY_MODULE) + if (mod->taints & TAINT_PROPRIETARY_MODULE) buf[bx++] = 'P'; - if (taints & TAINT_FORCED_MODULE) + if (mod->taints & TAINT_FORCED_MODULE) buf[bx++] = 'F'; /* * TAINT_FORCED_RMMOD: could be added. * TAINT_UNSAFE_SMP, TAINT_MACHINE_CHECK, TAINT_BAD_PAGE don't * apply to modules. */ + + /* Show a - for module-is-being-unloaded */ + if (mod->state == MODULE_STATE_GOING) + buf[bx++] = '-'; + /* Show a + for module-is-being-loaded */ + if (mod->state == MODULE_STATE_COMING) + buf[bx++] = '+'; buf[bx++] = ')'; } buf[bx] = '\0'; @@ -2401,7 +2453,7 @@ static int m_show(struct seq_file *m, void *p) /* Taints info */ if (mod->taints) - seq_printf(m, " %s", taint_flags(mod->taints, buf)); + seq_printf(m, " %s", module_flags(mod, buf)); seq_printf(m, "\n"); return 0; @@ -2496,7 +2548,9 @@ void print_modules(void) printk("Modules linked in:"); list_for_each_entry(mod, &modules, list) - printk(" %s%s", mod->name, taint_flags(mod->taints, buf)); + printk(" %s%s", mod->name, module_flags(mod, buf)); + if (last_unloaded_module[0]) + printk(" [last unloaded: %s]", last_unloaded_module); printk("\n"); } @@ -2507,7 +2561,7 @@ EXPORT_SYMBOL(struct_module); #endif #ifdef CONFIG_MARKERS -void module_update_markers(struct module *probe_module, int *refcount) +void module_update_markers(void) { struct module *mod; @@ -2515,8 +2569,7 @@ void module_update_markers(struct module *probe_module, int *refcount) list_for_each_entry(mod, &modules, list) if (!mod->taints) marker_update_probe_range(mod->markers, - mod->markers + mod->num_markers, - probe_module, refcount); + mod->markers + mod->num_markers); mutex_unlock(&module_mutex); } #endif