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/* Copyright (C) 2002 Richard Henderson Copyright (C) 2001 Rusty Russell, 2002 Rusty Russell IBM. This program is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 2 of the License, or (at your option) any later version. This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details. You should have received a copy of the GNU General Public License along with this program; if not, write to the Free Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA */ #include <linux/module.h> #include <linux/moduleloader.h> #include <linux/init.h> #include <linux/kallsyms.h> #include <linux/fs.h> #include <linux/sysfs.h> #include <linux/kernel.h> #include <linux/slab.h> #include <linux/vmalloc.h> #include <linux/elf.h> #include <linux/proc_fs.h> #include <linux/seq_file.h> #include <linux/syscalls.h> #include <linux/fcntl.h> #include <linux/rcupdate.h> #include <linux/capability.h> #include <linux/cpu.h> #include <linux/moduleparam.h> #include <linux/errno.h> #include <linux/err.h> #include <linux/vermagic.h> #include <linux/notifier.h> #include <linux/sched.h> #include <linux/stop_machine.h> #include <linux/device.h> #include <linux/string.h> #include <linux/mutex.h> #include <linux/unwind.h> #include <linux/rculist.h> #include <asm/uaccess.h> #include <asm/cacheflush.h> #include <linux/license.h> #include <asm/sections.h> #include <linux/tracepoint.h> #include <linux/ftrace.h> #if 0 #define DEBUGP printk #else #define DEBUGP(fmt , a...) #endif #ifndef ARCH_SHF_SMALL #define ARCH_SHF_SMALL 0 #endif /* If this is set, the section belongs in the init part of the module */ #define INIT_OFFSET_MASK (1UL << (BITS_PER_LONG-1)) /* List of modules, protected by module_mutex or preempt_disable * (delete uses stop_machine/add uses RCU list operations). */ 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); /* Bounds of module allocation, for speeding __module_text_address */ static unsigned long module_addr_min = -1UL, module_addr_max = 0; int register_module_notifier(struct notifier_block * nb) { return blocking_notifier_chain_register(&module_notify_list, nb); } EXPORT_SYMBOL(register_module_notifier); int unregister_module_notifier(struct notifier_block * nb) { return blocking_notifier_chain_unregister(&module_notify_list, nb); } EXPORT_SYMBOL(unregister_module_notifier); /* We require a truly strong try_module_get(): 0 means failure due to ongoing or failed initialization etc. */ 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; else return -ENOENT; } static inline void add_taint_module(struct module *mod, unsigned flag) { add_taint(flag); mod->taints |= (1U << flag); } /* * A thread that wants to hold a reference to a module only while it * is running can call this to safely exit. nfsd and lockd use this. */ void __module_put_and_exit(struct module *mod, long code) { module_put(mod); do_exit(code); } EXPORT_SYMBOL(__module_put_and_exit); /* Find a module section: 0 means not found. */ static unsigned int find_sec(Elf_Ehdr *hdr, Elf_Shdr *sechdrs, const char *secstrings, const char *name) { unsigned int i; for (i = 1; i < hdr->e_shnum; i++) /* Alloc bit cleared means "ignore it." */ if ((sechdrs[i].sh_flags & SHF_ALLOC) && strcmp(secstrings+sechdrs[i].sh_name, name) == 0) return i; return 0; } /* Find a module section, or NULL. */ static void *section_addr(Elf_Ehdr *hdr, Elf_Shdr *shdrs, const char *secstrings, const char *name) { /* Section 0 has sh_addr 0. */ return (void *)shdrs[find_sec(hdr, shdrs, secstrings, name)].sh_addr; } /* Find a module section, or NULL. Fill in number of "objects" in section. */ static void *section_objs(Elf_Ehdr *hdr, Elf_Shdr *sechdrs, const char *secstrings, const char *name, size_t object_size, unsigned int *num) { unsigned int sec = find_sec(hdr, sechdrs, secstrings, name); /* Section 0 has sh_addr 0 and sh_size 0. */ *num = sechdrs[sec].sh_size / object_size; return (void *)sechdrs[sec].sh_addr; } /* Provided by the linker */ extern const struct kernel_symbol __start___ksymtab[]; extern const struct kernel_symbol __stop___ksymtab[]; extern const struct kernel_symbol __start___ksymtab_gpl[]; extern const struct kernel_symbol __stop___ksymtab_gpl[]; extern const struct kernel_symbol __start___ksymtab_gpl_future[]; extern const struct kernel_symbol __stop___ksymtab_gpl_future[]; extern const struct kernel_symbol __start___ksymtab_gpl_future[]; extern const struct kernel_symbol __stop___ksymtab_gpl_future[]; extern const unsigned long __start___kcrctab[]; extern const unsigned long __start___kcrctab_gpl[]; extern const unsigned long __start___kcrctab_gpl_future[]; #ifdef CONFIG_UNUSED_SYMBOLS extern const struct kernel_symbol __start___ksymtab_unused[]; extern const struct kernel_symbol __stop___ksymtab_unused[]; extern const struct kernel_symbol __start___ksymtab_unused_gpl[]; extern const struct kernel_symbol __stop___ksymtab_unused_gpl[]; extern const unsigned long __start___kcrctab_unused[]; extern const unsigned long __start___kcrctab_unused_gpl[]; #endif #ifndef CONFIG_MODVERSIONS #define symversion(base, idx) NULL #else #define symversion(base, idx) ((base != NULL) ? ((base) + (idx)) : NULL) #endif struct symsearch { const struct kernel_symbol *start, *stop; const unsigned long *crcs; enum { NOT_GPL_ONLY, GPL_ONLY, WILL_BE_GPL_ONLY, } licence; bool unused; }; static bool each_symbol_in_section(const struct symsearch *arr, unsigned int arrsize, struct module *owner, bool (*fn)(const struct symsearch *syms, struct module *owner, unsigned int symnum, void *data), void *data) { unsigned int i, j; for (j = 0; j < arrsize; j++) { for (i = 0; i < arr[j].stop - arr[j].start; i++) if (fn(&arr[j], owner, i, data)) return true; } return false; } /* Returns true as soon as fn returns true, otherwise false. */ static bool each_symbol(bool (*fn)(const struct symsearch *arr, struct module *owner, unsigned int symnum, void *data), void *data) { struct module *mod; const struct symsearch arr[] = { { __start___ksymtab, __stop___ksymtab, __start___kcrctab, NOT_GPL_ONLY, false }, { __start___ksymtab_gpl, __stop___ksymtab_gpl, __start___kcrctab_gpl, GPL_ONLY, false }, { __start___ksymtab_gpl_future, __stop___ksymtab_gpl_future, __start___kcrctab_gpl_future, WILL_BE_GPL_ONLY, false }, #ifdef CONFIG_UNUSED_SYMBOLS { __start___ksymtab_unused, __stop___ksymtab_unused, __start___kcrctab_unused, NOT_GPL_ONLY, true }, { __start___ksymtab_unused_gpl, __stop___ksymtab_unused_gpl, __start___kcrctab_unused_gpl, GPL_ONLY, true }, #endif }; if (each_symbol_in_section(arr, ARRAY_SIZE(arr), NULL, fn, data)) return true; list_for_each_entry_rcu(mod, &modules, list) { struct symsearch arr[] = { { mod->syms, mod->syms + mod->num_syms, mod->crcs, NOT_GPL_ONLY, false }, { mod->gpl_syms, mod->gpl_syms + mod->num_gpl_syms, mod->gpl_crcs, GPL_ONLY, false }, { mod->gpl_future_syms, mod->gpl_future_syms + mod->num_gpl_future_syms, mod->gpl_future_crcs, WILL_BE_GPL_ONLY, false }, #ifdef CONFIG_UNUSED_SYMBOLS { mod->unused_syms, mod->unused_syms + mod->num_unused_syms, mod->unused_crcs, NOT_GPL_ONLY, true }, { mod->unused_gpl_syms, mod->unused_gpl_syms + mod->num_unused_gpl_syms, mod->unused_gpl_crcs, GPL_ONLY, true }, #endif }; if (each_symbol_in_section(arr, ARRAY_SIZE(arr), mod, fn, data)) return true; } return false; } struct find_symbol_arg { /* Input */ const char *name; bool gplok; bool warn; /* Output */ struct module *owner; const unsigned long *crc; unsigned long value; }; static bool find_symbol_in_section(const struct symsearch *syms, struct module *owner, unsigned int symnum, void *data) { struct find_symbol_arg *fsa = data; if (strcmp(syms->start[symnum].name, fsa->name) != 0) return false; if (!fsa->gplok) { if (syms->licence == GPL_ONLY) return false; if (syms->licence == WILL_BE_GPL_ONLY && fsa->warn) { printk(KERN_WARNING "Symbol %s is being used " "by a non-GPL module, which will not " "be allowed in the future\n", fsa->name); printk(KERN_WARNING "Please see the file " "Documentation/feature-removal-schedule.txt " "in the kernel source tree for more details.\n"); } } #ifdef CONFIG_UNUSED_SYMBOLS if (syms->unused && fsa->warn) { printk(KERN_WARNING "Symbol %s is marked as UNUSED, " "however this module is using it.\n", fsa->name); printk(KERN_WARNING "This symbol will go away in the future.\n"); printk(KERN_WARNING "Please evalute if this is the right api to use and if " "it really is, submit a report the linux kernel " "mailinglist together with submitting your code for " "inclusion.\n"); } #endif fsa->owner = owner; fsa->crc = symversion(syms->crcs, symnum); fsa->value = syms->start[symnum].value; return true; } /* Find a symbol, return value, (optional) crc and (optional) module * which owns it */ static unsigned long find_symbol(const char *name, struct module **owner, const unsigned long **crc, bool gplok, bool warn) { struct find_symbol_arg fsa; fsa.name = name; fsa.gplok = gplok; fsa.warn = warn; if (each_symbol(find_symbol_in_section, &fsa)) { if (owner) *owner = fsa.owner; if (crc) *crc = fsa.crc; return fsa.value; } DEBUGP("Failed to find symbol %s\n", name); return -ENOENT; } /* Search for module by name: must hold module_mutex. */ static struct module *find_module(const char *name) { struct module *mod; list_for_each_entry(mod, &modules, list) { if (strcmp(mod->name, name) == 0) return mod; } return NULL; } #ifdef CONFIG_SMP /* Number of blocks used and allocated. */ static unsigned int pcpu_num_used, pcpu_num_allocated; /* Size of each block. -ve means used. */ static int *pcpu_size; static int split_block(unsigned int i, unsigned short size) { /* Reallocation required? */ if (pcpu_num_used + 1 > pcpu_num_allocated) { int *new; new = krealloc(pcpu_size, sizeof(new[0])*pcpu_num_allocated*2, GFP_KERNEL); if (!new) return 0; pcpu_num_allocated *= 2; pcpu_size = new; } /* Insert a new subblock */ memmove(&pcpu_size[i+1], &pcpu_size[i], sizeof(pcpu_size[0]) * (pcpu_num_used - i)); pcpu_num_used++; pcpu_size[i+1] -= size; pcpu_size[i] = size; return 1; } static inline unsigned int block_size(int val) { if (val < 0) return -val; return val; } static void *percpu_modalloc(unsigned long size, unsigned long align, const char *name) { unsigned long extra; unsigned int i; void *ptr; if (align > PAGE_SIZE) { printk(KERN_WARNING "%s: per-cpu alignment %li > %li\n", name, align, PAGE_SIZE); align = PAGE_SIZE; } ptr = __per_cpu_start; for (i = 0; i < pcpu_num_used; ptr += block_size(pcpu_size[i]), i++) { /* Extra for alignment requirement. */ extra = ALIGN((unsigned long)ptr, align) - (unsigned long)ptr; BUG_ON(i == 0 && extra != 0); if (pcpu_size[i] < 0 || pcpu_size[i] < extra + size) continue; /* Transfer extra to previous block. */ if (pcpu_size[i-1] < 0) pcpu_size[i-1] -= extra; else pcpu_size[i-1] += extra; pcpu_size[i] -= extra; ptr += extra; /* Split block if warranted */ if (pcpu_size[i] - size > sizeof(unsigned long)) if (!split_block(i, size)) return NULL; /* Mark allocated */ pcpu_size[i] = -pcpu_size[i]; return ptr; } printk(KERN_WARNING "Could not allocate %lu bytes percpu data\n", size); return NULL; } static void percpu_modfree(void *freeme) { unsigned int i; void *ptr = __per_cpu_start + block_size(pcpu_size[0]); /* First entry is core kernel percpu data. */ for (i = 1; i < pcpu_num_used; ptr += block_size(pcpu_size[i]), i++) { if (ptr == freeme) { pcpu_size[i] = -pcpu_size[i]; goto free; } } BUG(); free: /* Merge with previous? */ if (pcpu_size[i-1] >= 0) { pcpu_size[i-1] += pcpu_size[i]; pcpu_num_used--; memmove(&pcpu_size[i], &pcpu_size[i+1], (pcpu_num_used - i) * sizeof(pcpu_size[0])); i--; } /* Merge with next? */ if (i+1 < pcpu_num_used && pcpu_size[i+1] >= 0) { pcpu_size[i] += pcpu_size[i+1]; pcpu_num_used--; memmove(&pcpu_size[i+1], &pcpu_size[i+2], (pcpu_num_used - (i+1)) * sizeof(pcpu_size[0])); } } static unsigned int find_pcpusec(Elf_Ehdr *hdr, Elf_Shdr *sechdrs, const char *secstrings) { 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; pcpu_num_allocated = 2; pcpu_size = kmalloc(sizeof(pcpu_size[0]) * pcpu_num_allocated, GFP_KERNEL); /* Static in-kernel percpu data (used). */ pcpu_size[0] = -(__per_cpu_end-__per_cpu_start); /* Free room. */ pcpu_size[1] = PERCPU_ENOUGH_ROOM + pcpu_size[0]; if (pcpu_size[1] < 0) { printk(KERN_ERR "No per-cpu room for modules.\n"); pcpu_num_used = 1; } return 0; } __initcall(percpu_modinit); #else /* ... !CONFIG_SMP */ static inline void *percpu_modalloc(unsigned long size, unsigned long align, const char *name) { return NULL; } static inline void percpu_modfree(void *pcpuptr) { BUG(); } static inline unsigned int find_pcpusec(Elf_Ehdr *hdr, Elf_Shdr *sechdrs, const char *secstrings) { return 0; } static inline void percpu_modcopy(void *pcpudst, const void *src, unsigned long size) { /* pcpusec should be 0, and size of that section should be 0. */ BUG_ON(size != 0); } #endif /* CONFIG_SMP */ #define MODINFO_ATTR(field) \ static void setup_modinfo_##field(struct module *mod, const char *s) \ { \ mod->field = kstrdup(s, GFP_KERNEL); \ } \ static ssize_t show_modinfo_##field(struct module_attribute *mattr, \ struct module *mod, char *buffer) \ { \ return sprintf(buffer, "%s\n", mod->field); \ } \ static int modinfo_##field##_exists(struct module *mod) \ { \ return mod->field != NULL; \ } \ static void free_modinfo_##field(struct module *mod) \ { \ kfree(mod->field); \ mod->field = NULL; \ } \ static struct module_attribute modinfo_##field = { \ .attr = { .name = __stringify(field), .mode = 0444 }, \ .show = show_modinfo_##field, \ .setup = setup_modinfo_##field, \ .test = modinfo_##field##_exists, \ .free = free_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) { unsigned int i; INIT_LIST_HEAD(&mod->modules_which_use_me); for (i = 0; i < NR_CPUS; i++) local_set(&mod->ref[i].count, 0); /* Hold reference count during initialization. */ local_set(&mod->ref[raw_smp_processor_id()].count, 1); /* Backwards compatibility macros put refcount during init. */ mod->waiter = current; } /* modules using other modules */ struct module_use { struct list_head list; struct module *module_which_uses; }; /* Does a already use b? */ static int already_uses(struct module *a, struct module *b) { struct module_use *use; list_for_each_entry(use, &b->modules_which_use_me, list) { if (use->module_which_uses == a) { DEBUGP("%s uses %s!\n", a->name, b->name); return 1; } } DEBUGP("%s does not use %s!\n", a->name, b->name); return 0; } /* Module a uses b */ static int use_module(struct module *a, struct module *b) { struct module_use *use; int no_warn, err; if (b == NULL || already_uses(a, b)) return 1; /* 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); use = kmalloc(sizeof(*use), GFP_ATOMIC); if (!use) { printk("%s: out of memory loading\n", a->name); module_put(b); return 0; } use->module_which_uses = a; list_add(&use->list, &b->modules_which_use_me); no_warn = sysfs_create_link(b->holders_dir, &a->mkobj.kobj, a->name); return 1; } /* Clear the unload stuff of the module. */ static void module_unload_free(struct module *mod) { struct module *i; list_for_each_entry(i, &modules, list) { struct module_use *use; list_for_each_entry(use, &i->modules_which_use_me, list) { if (use->module_which_uses == mod) { DEBUGP("%s unusing %s\n", mod->name, i->name); module_put(i); list_del(&use->list); kfree(use); sysfs_remove_link(i->holders_dir, mod->name); /* There can be at most one match. */ break; } } } } #ifdef CONFIG_MODULE_FORCE_UNLOAD static inline int try_force_unload(unsigned int flags) { int ret = (flags & O_TRUNC); if (ret) add_taint(TAINT_FORCED_RMMOD); return ret; } #else static inline int try_force_unload(unsigned int flags) { return 0; } #endif /* CONFIG_MODULE_FORCE_UNLOAD */ struct stopref { struct module *mod; int flags; int *forced; }; /* Whole machine is stopped with interrupts off when this runs. */ static int __try_stop_module(void *_sref) { struct stopref *sref = _sref; /* If it's not unused, quit unless we're forcing. */ if (module_refcount(sref->mod) != 0) { if (!(*sref->forced = try_force_unload(sref->flags))) return -EWOULDBLOCK; } /* Mark it as dying. */ sref->mod->state = MODULE_STATE_GOING; return 0; } static int try_stop_module(struct module *mod, int flags, int *forced) { if (flags & O_NONBLOCK) { struct stopref sref = { mod, flags, forced }; return stop_machine(__try_stop_module, &sref, NULL); } else { /* We don't need to stop the machine for this. */ mod->state = MODULE_STATE_GOING; synchronize_sched(); return 0; } } unsigned int module_refcount(struct module *mod) { unsigned int i, total = 0; for (i = 0; i < NR_CPUS; i++) total += local_read(&mod->ref[i].count); return total; } EXPORT_SYMBOL(module_refcount); /* This exists whether we can unload or not */ static void free_module(struct module *mod); static void wait_for_zero_refcount(struct module *mod) { /* Since we might sleep for some time, release the mutex first */ mutex_unlock(&module_mutex); for (;;) { DEBUGP("Looking at refcount...\n"); set_current_state(TASK_UNINTERRUPTIBLE); if (module_refcount(mod) == 0) break; schedule(); } current->state = TASK_RUNNING; mutex_lock(&module_mutex); } asmlinkage long sys_delete_module(const char __user *name_user, unsigned int flags) { struct module *mod; char name[MODULE_NAME_LEN]; int ret, forced = 0; if (!capable(CAP_SYS_MODULE)) return -EPERM; if (strncpy_from_user(name, name_user, MODULE_NAME_LEN-1) < 0) return -EFAULT; name[MODULE_NAME_LEN-1] = '\0'; if (mutex_lock_interruptible(&module_mutex) != 0) return -EINTR; mod = find_module(name); if (!mod) { ret = -ENOENT; goto out; } if (!list_empty(&mod->modules_which_use_me)) { /* Other modules depend on us: get rid of them first. */ ret = -EWOULDBLOCK; goto out; } /* Doing init or already dying? */ if (mod->state != MODULE_STATE_LIVE) { /* FIXME: if (force), slam module count and wake up waiter --RR */ DEBUGP("%s already dying\n", mod->name); ret = -EBUSY; goto out; } /* If it has an init func, it must have an exit func to unload */ if (mod->init && !mod->exit) { forced = try_force_unload(flags); if (!forced) { /* This module can't be removed */ ret = -EBUSY; goto out; } } /* Set this up before setting mod->state */ mod->waiter = current; /* Stop the machine so refcounts can't move and disable module. */ ret = try_stop_module(mod, flags, &forced); if (ret != 0) goto out; /* Never wait if forced. */ if (!forced && module_refcount(mod) != 0) wait_for_zero_refcount(mod); mutex_unlock(&module_mutex); /* Final destruction now noone is using it. */ if (mod->exit != NULL) mod->exit(); blocking_notifier_call_chain(&module_notify_list, MODULE_STATE_GOING, mod); 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)); unregister_dynamic_debug_module(mod->name); free_module(mod); out: mutex_unlock(&module_mutex); return ret; } static void print_unload_info(struct seq_file *m, struct module *mod) { struct module_use *use; int printed_something = 0; seq_printf(m, " %u ", module_refcount(mod)); /* Always include a trailing , so userspace can differentiate between this and the old multi-field proc format. */ list_for_each_entry(use, &mod->modules_which_use_me, list) { printed_something = 1; seq_printf(m, "%s,", use->module_which_uses->name); } if (mod->init != NULL && mod->exit == NULL) { printed_something = 1; seq_printf(m, "[permanent],"); } if (!printed_something) seq_printf(m, "-"); } void __symbol_put(const char *symbol) { struct module *owner; preempt_disable(); if (IS_ERR_VALUE(find_symbol(symbol, &owner, NULL, true, false))) BUG(); module_put(owner); preempt_enable(); } EXPORT_SYMBOL(__symbol_put); void symbol_put_addr(void *addr) { struct module *modaddr; if (core_kernel_text((unsigned long)addr)) return; if (!(modaddr = module_text_address((unsigned long)addr))) BUG(); module_put(modaddr); } EXPORT_SYMBOL_GPL(symbol_put_addr); static ssize_t show_refcnt(struct module_attribute *mattr, struct module *mod, char *buffer) { return sprintf(buffer, "%u\n", module_refcount(mod)); } static struct module_attribute refcnt = { .attr = { .name = "refcnt", .mode = 0444 }, .show = show_refcnt, }; void module_put(struct module *module) { if (module) { unsigned int cpu = get_cpu(); local_dec(&module->ref[cpu].count); /* Maybe they're waiting for us to drop reference? */ if (unlikely(!module_is_live(module))) wake_up_process(module->waiter); put_cpu(); } } EXPORT_SYMBOL(module_put); #else /* !CONFIG_MODULE_UNLOAD */ static void print_unload_info(struct seq_file *m, struct module *mod) { /* We don't know the usage count, or what modules are using. */ seq_printf(m, " - -"); } 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) == 0; } static inline void module_unload_init(struct module *mod) { } #endif /* CONFIG_MODULE_UNLOAD */ static ssize_t show_initstate(struct module_attribute *mattr, struct module *mod, char *buffer) { const char *state = "unknown"; switch (mod->state) { case MODULE_STATE_LIVE: state = "live"; break; case MODULE_STATE_COMING: state = "coming"; break; case MODULE_STATE_GOING: state = "going"; break; } return sprintf(buffer, "%s\n", state); } static struct module_attribute initstate = { .attr = { .name = "initstate", .mode = 0444 }, .show = show_initstate, }; static struct module_attribute *modinfo_attrs[] = { &modinfo_version, &modinfo_srcversion, &initstate, #ifdef CONFIG_MODULE_UNLOAD &refcnt, #endif NULL, }; static const char vermagic[] = VERMAGIC_STRING; static int try_to_force_load(struct module *mod, const char *symname) { #ifdef CONFIG_MODULE_FORCE_LOAD if (!test_taint(TAINT_FORCED_MODULE)) printk("%s: no version for \"%s\" found: kernel tainted.\n", mod->name, symname); add_taint_module(mod, TAINT_FORCED_MODULE); return 0; #else return -ENOEXEC; #endif } #ifdef CONFIG_MODVERSIONS static int check_version(Elf_Shdr *sechdrs, unsigned int versindex, const char *symname, struct module *mod, const unsigned long *crc) { unsigned int i, num_versions; struct modversion_info *versions; /* Exporting module didn't supply crcs? OK, we're already tainted. */ if (!crc) return 1; /* No versions at all? modprobe --force does this. */ if (versindex == 0) return try_to_force_load(mod, symname) == 0; versions = (void *) sechdrs[versindex].sh_addr; num_versions = sechdrs[versindex].sh_size / sizeof(struct modversion_info); for (i = 0; i < num_versions; i++) { if (strcmp(versions[i].name, symname) != 0) continue; if (versions[i].crc == *crc) return 1; DEBUGP("Found checksum %lX vs module %lX\n", *crc, versions[i].crc); goto bad_version; } printk(KERN_WARNING "%s: no symbol version for %s\n", mod->name, symname); return 0; bad_version: printk("%s: disagrees about version of symbol %s\n", mod->name, symname); return 0; } static inline int check_modstruct_version(Elf_Shdr *sechdrs, unsigned int versindex, struct module *mod) { const unsigned long *crc; if (IS_ERR_VALUE(find_symbol("struct_module", NULL, &crc, true, false))) BUG(); return check_version(sechdrs, versindex, "struct_module", mod, crc); } /* First part is kernel version, which we ignore if module has crcs. */ static inline int same_magic(const char *amagic, const char *bmagic, bool has_crcs) { if (has_crcs) { amagic += strcspn(amagic, " "); bmagic += strcspn(bmagic, " "); } return strcmp(amagic, bmagic) == 0; } #else static inline int check_version(Elf_Shdr *sechdrs, unsigned int versindex, const char *symname, struct module *mod, const unsigned long *crc) { return 1; } static inline int check_modstruct_version(Elf_Shdr *sechdrs, unsigned int versindex, struct module *mod) { return 1; } static inline int same_magic(const char *amagic, const char *bmagic, bool has_crcs) { return strcmp(amagic, bmagic) == 0; } #endif /* CONFIG_MODVERSIONS */ /* Resolve a symbol for this module. I.e. if we find one, record usage. Must be holding module_mutex. */ static unsigned long resolve_symbol(Elf_Shdr *sechdrs, unsigned int versindex, const char *name, struct module *mod) { struct module *owner; unsigned long ret; const unsigned long *crc; ret = find_symbol(name, &owner, &crc, !(mod->taints & (1 << TAINT_PROPRIETARY_MODULE)), true); 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 = -EINVAL; } return ret; } /* * /sys/module/foo/sections stuff * J. Corbet <corbet@lwn.net> */ #if defined(CONFIG_KALLSYMS) && defined(CONFIG_SYSFS) struct module_sect_attr { struct module_attribute mattr; char *name; unsigned long address; }; struct module_sect_attrs { struct attribute_group grp; unsigned int nsections; struct module_sect_attr attrs[0]; }; static ssize_t module_sect_show(struct module_attribute *mattr, struct module *mod, char *buf) { struct module_sect_attr *sattr = container_of(mattr, struct module_sect_attr, mattr); return sprintf(buf, "0x%lx\n", sattr->address); } static void free_sect_attrs(struct module_sect_attrs *sect_attrs) { unsigned int section; for (section = 0; section < sect_attrs->nsections; section++) kfree(sect_attrs->attrs[section].name); kfree(sect_attrs); } static void add_sect_attrs(struct module *mod, unsigned int nsect, char *secstrings, Elf_Shdr *sechdrs) { unsigned int nloaded = 0, i, size[2]; struct module_sect_attrs *sect_attrs; struct module_sect_attr *sattr; struct attribute **gattr; /* Count loaded sections and allocate structures */ for (i = 0; i < nsect; i++) if (sechdrs[i].sh_flags & SHF_ALLOC) nloaded++; size[0] = ALIGN(sizeof(*sect_attrs) + nloaded * sizeof(sect_attrs->attrs[0]), sizeof(sect_attrs->grp.attrs[0])); size[1] = (nloaded + 1) * sizeof(sect_attrs->grp.attrs[0]); sect_attrs = kzalloc(size[0] + size[1], GFP_KERNEL); if (sect_attrs == NULL) return; /* Setup section attributes. */ sect_attrs->grp.name = "sections"; sect_attrs->grp.attrs = (void *)sect_attrs + size[0]; sect_attrs->nsections = 0; sattr = &sect_attrs->attrs[0]; gattr = &sect_attrs->grp.attrs[0]; for (i = 0; i < nsect; i++) { if (! (sechdrs[i].sh_flags & SHF_ALLOC)) continue; sattr->address = sechdrs[i].sh_addr; sattr->name = kstrdup(secstrings + sechdrs[i].sh_name, GFP_KERNEL); if (sattr->name == NULL) goto out; sect_attrs->nsections++; sattr->mattr.show = module_sect_show; sattr->mattr.store = NULL; sattr->mattr.attr.name = sattr->name; sattr->mattr.attr.mode = S_IRUGO; *(gattr++) = &(sattr++)->mattr.attr; } *gattr = NULL; if (sysfs_create_group(&mod->mkobj.kobj, &sect_attrs->grp)) goto out; mod->sect_attrs = sect_attrs; return; out: free_sect_attrs(sect_attrs); } static void remove_sect_attrs(struct module *mod) { if (mod->sect_attrs) { sysfs_remove_group(&mod->mkobj.kobj, &mod->sect_attrs->grp); /* We are positive that no one is using any sect attrs * at this point. Deallocate immediately. */ free_sect_attrs(mod->sect_attrs); mod->sect_attrs = NULL; } } /* * /sys/module/foo/notes/.section.name gives contents of SHT_NOTE sections. */ struct module_notes_attrs { struct kobject *dir; unsigned int notes; struct bin_attribute attrs[0]; }; static ssize_t module_notes_read(struct kobject *kobj, struct bin_attribute *bin_attr, char *buf, loff_t pos, size_t count) { /* * The caller checked the pos and count against our size. */ memcpy(buf, bin_attr->private + pos, count); return count; } static void free_notes_attrs(struct module_notes_attrs *notes_attrs, unsigned int i) { if (notes_attrs->dir) { while (i-- > 0) sysfs_remove_bin_file(notes_attrs->dir, &notes_attrs->attrs[i]); kobject_put(notes_attrs->dir); } kfree(notes_attrs); } static void add_notes_attrs(struct module *mod, unsigned int nsect, char *secstrings, Elf_Shdr *sechdrs) { unsigned int notes, loaded, i; struct module_notes_attrs *notes_attrs; struct bin_attribute *nattr; /* Count notes sections and allocate structures. */ notes = 0; for (i = 0; i < nsect; i++) if ((sechdrs[i].sh_flags & SHF_ALLOC) && (sechdrs[i].sh_type == SHT_NOTE)) ++notes; if (notes == 0) return; notes_attrs = kzalloc(sizeof(*notes_attrs) + notes * sizeof(notes_attrs->attrs[0]), GFP_KERNEL); if (notes_attrs == NULL) return; notes_attrs->notes = notes; nattr = &notes_attrs->attrs[0]; for (loaded = i = 0; i < nsect; ++i) { if (!(sechdrs[i].sh_flags & SHF_ALLOC)) continue; if (sechdrs[i].sh_type == SHT_NOTE) { nattr->attr.name = mod->sect_attrs->attrs[loaded].name; nattr->attr.mode = S_IRUGO; nattr->size = sechdrs[i].sh_size; nattr->private = (void *) sechdrs[i].sh_addr; nattr->read = module_notes_read; ++nattr; } ++loaded; } notes_attrs->dir = kobject_create_and_add("notes", &mod->mkobj.kobj); if (!notes_attrs->dir) goto out; for (i = 0; i < notes; ++i) if (sysfs_create_bin_file(notes_attrs->dir, &notes_attrs->attrs[i])) goto out; mod->notes_attrs = notes_attrs; return; out: free_notes_attrs(notes_attrs, i); } static void remove_notes_attrs(struct module *mod) { if (mod->notes_attrs) free_notes_attrs(mod->notes_attrs, mod->notes_attrs->notes); } #else static inline void add_sect_attrs(struct module *mod, unsigned int nsect, char *sectstrings, Elf_Shdr *sechdrs) { } static inline void remove_sect_attrs(struct module *mod) { } static inline void add_notes_attrs(struct module *mod, unsigned int nsect, char *sectstrings, Elf_Shdr *sechdrs) { } static inline void remove_notes_attrs(struct module *mod) { } #endif #ifdef CONFIG_SYSFS int module_add_modinfo_attrs(struct module *mod) { struct module_attribute *attr; struct module_attribute *temp_attr; int error = 0; int i; mod->modinfo_attrs = kzalloc((sizeof(struct module_attribute) * (ARRAY_SIZE(modinfo_attrs) + 1)), GFP_KERNEL); if (!mod->modinfo_attrs) return -ENOMEM; temp_attr = mod->modinfo_attrs; for (i = 0; (attr = modinfo_attrs[i]) && !error; i++) { if (!attr->test || (attr->test && attr->test(mod))) { memcpy(temp_attr, attr, sizeof(*temp_attr)); error = sysfs_create_file(&mod->mkobj.kobj,&temp_attr->attr); ++temp_attr; } } return error; } void module_remove_modinfo_attrs(struct module *mod) { struct module_attribute *attr; int i; for (i = 0; (attr = &mod->modinfo_attrs[i]); i++) { /* pick a field to test for end of list */ if (!attr->attr.name) break; sysfs_remove_file(&mod->mkobj.kobj,&attr->attr); if (attr->free) attr->free(mod); } kfree(mod->modinfo_attrs); } 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", mod->name); err = -EINVAL; goto out; } 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.mod = mod; 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 */ out: return err; } int mod_sysfs_setup(struct module *mod, struct kernel_param *kparam, unsigned int num_params) { int err; mod->holders_dir = kobject_create_and_add("holders", &mod->mkobj.kobj); if (!mod->holders_dir) { err = -ENOMEM; goto out_unreg; } err = module_param_sysfs_setup(mod, kparam, num_params); if (err) goto out_unreg_holders; err = module_add_modinfo_attrs(mod); if (err) goto out_unreg_param; kobject_uevent(&mod->mkobj.kobj, KOBJ_ADD); return 0; out_unreg_param: module_param_sysfs_remove(mod); out_unreg_holders: kobject_put(mod->holders_dir); out_unreg: kobject_put(&mod->mkobj.kobj); return err; } static void mod_sysfs_fini(struct module *mod) { kobject_put(&mod->mkobj.kobj); } #else /* CONFIG_SYSFS */ static void mod_sysfs_fini(struct module *mod) { } #endif /* CONFIG_SYSFS */ static void mod_kobject_remove(struct module *mod) { module_remove_modinfo_attrs(mod); module_param_sysfs_remove(mod); kobject_put(mod->mkobj.drivers_dir); kobject_put(mod->holders_dir); mod_sysfs_fini(mod); } /* * unlink the module with the whole machine is stopped with interrupts off * - this defends against kallsyms not taking locks */ static int __unlink_module(void *_mod) { struct module *mod = _mod; list_del(&mod->list); return 0; } /* Free a module, remove from lists, etc (must hold module_mutex). */ static void free_module(struct module *mod) { /* Delete from various lists */ stop_machine(__unlink_module, mod, NULL); remove_notes_attrs(mod); remove_sect_attrs(mod); mod_kobject_remove(mod); unwind_remove_table(mod->unwind_info, 0); /* Arch-specific cleanup. */ module_arch_cleanup(mod); /* Module unload stuff */ module_unload_free(mod); /* release any pointers to mcount in this module */ ftrace_release(mod->module_core, mod->core_size); /* This may be NULL, but that's OK */ module_free(mod, mod->module_init); kfree(mod->args); if (mod->percpu) percpu_modfree(mod->percpu); /* Free lock-classes: */ lockdep_free_key_range(mod->module_core, mod->core_size); /* Finally, free the core (containing the module structure) */ module_free(mod, mod->module_core); } void *__symbol_get(const char *symbol) { struct module *owner; unsigned long value; preempt_disable(); value = find_symbol(symbol, &owner, NULL, true, true); if (IS_ERR_VALUE(value)) value = 0; else if (strong_try_module_get(owner)) value = 0; preempt_enable(); return (void *)value; } EXPORT_SYMBOL_GPL(__symbol_get); /* * Ensure that an exported symbol [global namespace] does not already exist * in the kernel or in some other module's exported symbol table. */ static int verify_export_symbols(struct module *mod) { unsigned int i; struct module *owner; const struct kernel_symbol *s; struct { const struct kernel_symbol *sym; unsigned int num; } arr[] = { { mod->syms, mod->num_syms }, { mod->gpl_syms, mod->num_gpl_syms }, { mod->gpl_future_syms, mod->num_gpl_future_syms }, #ifdef CONFIG_UNUSED_SYMBOLS { mod->unused_syms, mod->num_unused_syms }, { mod->unused_gpl_syms, mod->num_unused_gpl_syms }, #endif }; for (i = 0; i < ARRAY_SIZE(arr); i++) { for (s = arr[i].sym; s < arr[i].sym + arr[i].num; s++) { if (!IS_ERR_VALUE(find_symbol(s->name, &owner, NULL, true, false))) { printk(KERN_ERR "%s: exports duplicate symbol %s" " (owned by %s)\n", mod->name, s->name, module_name(owner)); return -ENOEXEC; } } } return 0; } /* Change all symbols so that st_value encodes the pointer directly. */ static int simplify_symbols(Elf_Shdr *sechdrs, unsigned int symindex, const char *strtab, unsigned int versindex, unsigned int pcpuindex, struct module *mod) { Elf_Sym *sym = (void *)sechdrs[symindex].sh_addr; unsigned long secbase; unsigned int i, n = sechdrs[symindex].sh_size / sizeof(Elf_Sym); int ret = 0; for (i = 1; i < n; i++) { switch (sym[i].st_shndx) { case SHN_COMMON: /* We compiled with -fno-common. These are not supposed to happen. */ DEBUGP("Common symbol: %s\n", strtab + sym[i].st_name); printk("%s: please compile with -fno-common\n", mod->name); ret = -ENOEXEC; break; case SHN_ABS: /* Don't need to do anything */ DEBUGP("Absolute symbol: 0x%08lx\n", (long)sym[i].st_value); break; case SHN_UNDEF: sym[i].st_value = resolve_symbol(sechdrs, versindex, strtab + sym[i].st_name, mod); /* Ok if resolved. */ if (!IS_ERR_VALUE(sym[i].st_value)) break; /* Ok if weak. */ if (ELF_ST_BIND(sym[i].st_info) == STB_WEAK) break; printk(KERN_WARNING "%s: Unknown symbol %s\n", mod->name, strtab + sym[i].st_name); ret = -ENOENT; break; default: /* Divert to percpu allocation if a percpu var. */ if (sym[i].st_shndx == pcpuindex) secbase = (unsigned long)mod->percpu; else secbase = sechdrs[sym[i].st_shndx].sh_addr; sym[i].st_value += secbase; break; } } return ret; } /* Update size with this section: return offset. */ static long get_offset(unsigned int *size, Elf_Shdr *sechdr) { long ret; ret = ALIGN(*size, sechdr->sh_addralign ?: 1); *size = ret + sechdr->sh_size; return ret; } /* Lay out the SHF_ALLOC sections in a way not dissimilar to how ld might -- code, read-only data, read-write data, small data. Tally sizes, and place the offsets into sh_entsize fields: high bit means it belongs in init. */ static void layout_sections(struct module *mod, const Elf_Ehdr *hdr, Elf_Shdr *sechdrs, const char *secstrings) { static unsigned long const masks[][2] = { /* NOTE: all executable code must be the first section * in this array; otherwise modify the text_size * finder in the two loops below */ { SHF_EXECINSTR | SHF_ALLOC, ARCH_SHF_SMALL }, { SHF_ALLOC, SHF_WRITE | ARCH_SHF_SMALL }, { SHF_WRITE | SHF_ALLOC, ARCH_SHF_SMALL }, { ARCH_SHF_SMALL | SHF_ALLOC, 0 } }; unsigned int m, i; for (i = 0; i < hdr->e_shnum; i++) sechdrs[i].sh_entsize = ~0UL; DEBUGP("Core section allocation order:\n"); for (m = 0; m < ARRAY_SIZE(masks); ++m) { for (i = 0; i < hdr->e_shnum; ++i) { Elf_Shdr *s = &sechdrs[i]; if ((s->sh_flags & masks[m][0]) != masks[m][0] || (s->sh_flags & masks[m][1]) || s->sh_entsize != ~0UL || strncmp(secstrings + s->sh_name, ".init", 5) == 0) continue; s->sh_entsize = get_offset(&mod->core_size, s); DEBUGP("\t%s\n", secstrings + s->sh_name); } if (m == 0) mod->core_text_size = mod->core_size; } DEBUGP("Init section allocation order:\n"); for (m = 0; m < ARRAY_SIZE(masks); ++m) { for (i = 0; i < hdr->e_shnum; ++i) { Elf_Shdr *s = &sechdrs[i]; if ((s->sh_flags & masks[m][0]) != masks[m][0] || (s->sh_flags & masks[m][1]) || s->sh_entsize != ~0UL || strncmp(secstrings + s->sh_name, ".init", 5) != 0) continue; s->sh_entsize = (get_offset(&mod->init_size, s) | INIT_OFFSET_MASK); DEBUGP("\t%s\n", secstrings + s->sh_name); } if (m == 0) mod->init_text_size = mod->init_size; } } static void set_license(struct module *mod, const char *license) { if (!license) license = "unspecified"; if (!license_is_gpl_compatible(license)) { if (!test_taint(TAINT_PROPRIETARY_MODULE)) printk(KERN_WARNING "%s: module license '%s' taints " "kernel.\n", mod->name, license); add_taint_module(mod, TAINT_PROPRIETARY_MODULE); } } /* Parse tag=value strings from .modinfo section */ static char *next_string(char *string, unsigned long *secsize) { /* Skip non-zero chars */ while (string[0]) { string++; if ((*secsize)-- <= 1) return NULL; } /* Skip any zero padding. */ while (!string[0]) { string++; if ((*secsize)-- <= 1) return NULL; } return string; } static char *get_modinfo(Elf_Shdr *sechdrs, unsigned int info, const char *tag) { char *p; unsigned int taglen = strlen(tag); unsigned long size = sechdrs[info].sh_size; for (p = (char *)sechdrs[info].sh_addr; p; p = next_string(p, &size)) { if (strncmp(p, tag, taglen) == 0 && p[taglen] == '=') return p + taglen + 1; } return NULL; } static void setup_modinfo(struct module *mod, Elf_Shdr *sechdrs, unsigned int infoindex) { struct module_attribute *attr; int i; for (i = 0; (attr = modinfo_attrs[i]); i++) { if (attr->setup) attr->setup(mod, get_modinfo(sechdrs, infoindex, attr->attr.name)); } } #ifdef CONFIG_KALLSYMS /* lookup symbol in given range of kernel_symbols */ static const struct kernel_symbol *lookup_symbol(const char *name, const struct kernel_symbol *start, const struct kernel_symbol *stop) { const struct kernel_symbol *ks = start; for (; ks < stop; ks++) if (strcmp(ks->name, name) == 0) return ks; return NULL; } static int is_exported(const char *name, const struct module *mod) { if (!mod && lookup_symbol(name, __start___ksymtab, __stop___ksymtab)) return 1; else if (mod && lookup_symbol(name, mod->syms, mod->syms + mod->num_syms)) return 1; else return 0; } /* As per nm */ static char elf_type(const Elf_Sym *sym, Elf_Shdr *sechdrs, const char *secstrings, struct module *mod) { if (ELF_ST_BIND(sym->st_info) == STB_WEAK) { if (ELF_ST_TYPE(sym->st_info) == STT_OBJECT) return 'v'; else return 'w'; } if (sym->st_shndx == SHN_UNDEF) return 'U'; if (sym->st_shndx == SHN_ABS) return 'a'; if (sym->st_shndx >= SHN_LORESERVE) return '?'; if (sechdrs[sym->st_shndx].sh_flags & SHF_EXECINSTR) return 't'; if (sechdrs[sym->st_shndx].sh_flags & SHF_ALLOC && sechdrs[sym->st_shndx].sh_type != SHT_NOBITS) { if (!(sechdrs[sym->st_shndx].sh_flags & SHF_WRITE)) return 'r'; else if (sechdrs[sym->st_shndx].sh_flags & ARCH_SHF_SMALL) return 'g'; else return 'd'; } if (sechdrs[sym->st_shndx].sh_type == SHT_NOBITS) { if (sechdrs[sym->st_shndx].sh_flags & ARCH_SHF_SMALL) return 's'; else return 'b'; } if (strncmp(secstrings + sechdrs[sym->st_shndx].sh_name, ".debug", strlen(".debug")) == 0) return 'n'; return '?'; } static void add_kallsyms(struct module *mod, Elf_Shdr *sechdrs, unsigned int symindex, unsigned int strindex, const char *secstrings) { unsigned int i; mod->symtab = (void *)sechdrs[symindex].sh_addr; mod->num_symtab = sechdrs[symindex].sh_size / sizeof(Elf_Sym); mod->strtab = (void *)sechdrs[strindex].sh_addr; /* Set types up while we still have access to sections. */ for (i = 0; i < mod->num_symtab; i++) mod->symtab[i].st_info = elf_type(&mod->symtab[i], sechdrs, secstrings, mod); } #else static inline void add_kallsyms(struct module *mod, Elf_Shdr *sechdrs, unsigned int symindex, unsigned int strindex, const char *secstrings) { } #endif /* CONFIG_KALLSYMS */ static void dynamic_printk_setup(struct mod_debug *debug, unsigned int num) { #ifdef CONFIG_DYNAMIC_PRINTK_DEBUG unsigned int i; for (i = 0; i < num; i++) { register_dynamic_debug_module(debug[i].modname, debug[i].type, debug[i].logical_modname, debug[i].flag_names, debug[i].hash, debug[i].hash2); } #endif /* CONFIG_DYNAMIC_PRINTK_DEBUG */ } static void *module_alloc_update_bounds(unsigned long size) { void *ret = module_alloc(size); if (ret) { /* Update module bounds. */ if ((unsigned long)ret < module_addr_min) module_addr_min = (unsigned long)ret; if ((unsigned long)ret + size > module_addr_max) module_addr_max = (unsigned long)ret + size; } return ret; } /* Allocate and load the module: note that size of section 0 is always zero, and we rely on this for optional sections. */ static noinline struct module *load_module(void __user *umod, unsigned long len, const char __user *uargs) { Elf_Ehdr *hdr; Elf_Shdr *sechdrs; char *secstrings, *args, *modmagic, *strtab = NULL; char *staging; unsigned int i; unsigned int symindex = 0; unsigned int strindex = 0; unsigned int modindex, versindex, infoindex, pcpuindex; unsigned int unwindex = 0; unsigned int num_kp, num_mcount; struct kernel_param *kp; struct module *mod; long err = 0; void *percpu = NULL, *ptr = NULL; /* Stops spurious gcc warning */ unsigned long *mseg; mm_segment_t old_fs; DEBUGP("load_module: umod=%p, len=%lu, uargs=%p\n", umod, len, uargs); if (len < sizeof(*hdr)) return ERR_PTR(-ENOEXEC); /* Suck in entire file: we'll want most of it. */ /* vmalloc barfs on "unusual" numbers. Check here */ if (len > 64 * 1024 * 1024 || (hdr = vmalloc(len)) == NULL) return ERR_PTR(-ENOMEM); if (copy_from_user(hdr, umod, len) != 0) { err = -EFAULT; goto free_hdr; } /* Sanity checks against insmoding binaries or wrong arch, weird elf version */ if (memcmp(hdr->e_ident, ELFMAG, SELFMAG) != 0 || hdr->e_type != ET_REL || !elf_check_arch(hdr) || hdr->e_shentsize != sizeof(*sechdrs)) { err = -ENOEXEC; goto free_hdr; } if (len < hdr->e_shoff + hdr->e_shnum * sizeof(Elf_Shdr)) goto truncated; /* Convenience variables */ sechdrs = (void *)hdr + hdr->e_shoff; secstrings = (void *)hdr + sechdrs[hdr->e_shstrndx].sh_offset; sechdrs[0].sh_addr = 0; for (i = 1; i < hdr->e_shnum; i++) { if (sechdrs[i].sh_type != SHT_NOBITS && len < sechdrs[i].sh_offset + sechdrs[i].sh_size) goto truncated; /* Mark all sections sh_addr with their address in the temporary image. */ sechdrs[i].sh_addr = (size_t)hdr + sechdrs[i].sh_offset; /* Internal symbols and strings. */ if (sechdrs[i].sh_type == SHT_SYMTAB) { symindex = i; strindex = sechdrs[i].sh_link; strtab = (char *)hdr + sechdrs[strindex].sh_offset; } #ifndef CONFIG_MODULE_UNLOAD /* Don't load .exit sections */ if (strncmp(secstrings+sechdrs[i].sh_name, ".exit", 5) == 0) sechdrs[i].sh_flags &= ~(unsigned long)SHF_ALLOC; #endif } modindex = find_sec(hdr, sechdrs, secstrings, ".gnu.linkonce.this_module"); if (!modindex) { printk(KERN_WARNING "No module found in object\n"); err = -ENOEXEC; goto free_hdr; } /* This is temporary: point mod into copy of data. */ mod = (void *)sechdrs[modindex].sh_addr; if (symindex == 0) { printk(KERN_WARNING "%s: module has no symbols (stripped?)\n", mod->name); err = -ENOEXEC; goto free_hdr; } versindex = find_sec(hdr, sechdrs, secstrings, "__versions"); infoindex = find_sec(hdr, sechdrs, secstrings, ".modinfo"); pcpuindex = find_pcpusec(hdr, sechdrs, secstrings); #ifdef ARCH_UNWIND_SECTION_NAME unwindex = find_sec(hdr, sechdrs, secstrings, ARCH_UNWIND_SECTION_NAME); #endif /* Don't keep modinfo and version sections. */ sechdrs[infoindex].sh_flags &= ~(unsigned long)SHF_ALLOC; sechdrs[versindex].sh_flags &= ~(unsigned long)SHF_ALLOC; #ifdef CONFIG_KALLSYMS /* Keep symbol and string tables for decoding later. */ sechdrs[symindex].sh_flags |= SHF_ALLOC; sechdrs[strindex].sh_flags |= SHF_ALLOC; #endif if (unwindex) sechdrs[unwindex].sh_flags |= SHF_ALLOC; /* Check module struct version now, before we try to use module. */ if (!check_modstruct_version(sechdrs, versindex, mod)) { err = -ENOEXEC; goto free_hdr; } modmagic = get_modinfo(sechdrs, infoindex, "vermagic"); /* This is allowed: modprobe --force will invalidate it. */ if (!modmagic) { err = try_to_force_load(mod, "magic"); if (err) goto free_hdr; } else if (!same_magic(modmagic, vermagic, versindex)) { printk(KERN_ERR "%s: version magic '%s' should be '%s'\n", mod->name, modmagic, vermagic); err = -ENOEXEC; goto free_hdr; } staging = get_modinfo(sechdrs, infoindex, "staging"); if (staging) { add_taint_module(mod, TAINT_CRAP); printk(KERN_WARNING "%s: module is from the staging directory," " the quality is unknown, you have been warned.\n", mod->name); } /* Now copy in args */ args = strndup_user(uargs, ~0UL >> 1); if (IS_ERR(args)) { err = PTR_ERR(args); goto free_hdr; } if (find_module(mod->name)) { err = -EEXIST; goto free_mod; } mod->state = MODULE_STATE_COMING; /* Allow arches to frob section contents and sizes. */ err = module_frob_arch_sections(hdr, sechdrs, secstrings, mod); if (err < 0) goto free_mod; if (pcpuindex) { /* We have a special allocation for this section. */ percpu = percpu_modalloc(sechdrs[pcpuindex].sh_size, sechdrs[pcpuindex].sh_addralign, mod->name); if (!percpu) { err = -ENOMEM; goto free_mod; } sechdrs[pcpuindex].sh_flags &= ~(unsigned long)SHF_ALLOC; mod->percpu = percpu; } /* Determine total sizes, and put offsets in sh_entsize. For now this is done generically; there doesn't appear to be any special cases for the architectures. */ layout_sections(mod, hdr, sechdrs, secstrings); /* Do the allocs. */ ptr = module_alloc_update_bounds(mod->core_size); if (!ptr) { err = -ENOMEM; goto free_percpu; } memset(ptr, 0, mod->core_size); mod->module_core = ptr; ptr = module_alloc_update_bounds(mod->init_size); if (!ptr && mod->init_size) { err = -ENOMEM; goto free_core; } memset(ptr, 0, mod->init_size); mod->module_init = ptr; /* Transfer each section which specifies SHF_ALLOC */ DEBUGP("final section addresses:\n"); for (i = 0; i < hdr->e_shnum; i++) { void *dest; if (!(sechdrs[i].sh_flags & SHF_ALLOC)) continue; if (sechdrs[i].sh_entsize & INIT_OFFSET_MASK) dest = mod->module_init + (sechdrs[i].sh_entsize & ~INIT_OFFSET_MASK); else dest = mod->module_core + sechdrs[i].sh_entsize; if (sechdrs[i].sh_type != SHT_NOBITS) memcpy(dest, (void *)sechdrs[i].sh_addr, sechdrs[i].sh_size); /* Update sh_addr to point to copy in image. */ sechdrs[i].sh_addr = (unsigned long)dest; DEBUGP("\t0x%lx %s\n", sechdrs[i].sh_addr, secstrings + sechdrs[i].sh_name); } /* Module has been moved. */ mod = (void *)sechdrs[modindex].sh_addr; /* Now we've moved module, initialize linked lists, etc. */ module_unload_init(mod); /* add kobject, so we can reference it. */ err = mod_sysfs_init(mod); if (err) goto free_unload; /* Set up license info based on the info section */ set_license(mod, get_modinfo(sechdrs, infoindex, "license")); /* * ndiswrapper is under GPL by itself, but loads proprietary modules. * Don't use add_taint_module(), as it would prevent ndiswrapper from * using GPL-only symbols it needs. */ if (strcmp(mod->name, "ndiswrapper") == 0) add_taint(TAINT_PROPRIETARY_MODULE); /* driverloader was caught wrongly pretending to be under GPL */ if (strcmp(mod->name, "driverloader") == 0) add_taint_module(mod, TAINT_PROPRIETARY_MODULE); /* Set up MODINFO_ATTR fields */ setup_modinfo(mod, sechdrs, infoindex); /* Fix up syms, so that st_value is a pointer to location. */ err = simplify_symbols(sechdrs, symindex, strtab, versindex, pcpuindex, mod); if (err < 0) goto cleanup; /* Now we've got everything in the final locations, we can * find optional sections. */ kp = section_objs(hdr, sechdrs, secstrings, "__param", sizeof(*kp), &num_kp); mod->syms = section_objs(hdr, sechdrs, secstrings, "__ksymtab", sizeof(*mod->syms), &mod->num_syms); mod->crcs = section_addr(hdr, sechdrs, secstrings, "__kcrctab"); mod->gpl_syms = section_objs(hdr, sechdrs, secstrings, "__ksymtab_gpl", sizeof(*mod->gpl_syms), &mod->num_gpl_syms); mod->gpl_crcs = section_addr(hdr, sechdrs, secstrings, "__kcrctab_gpl"); mod->gpl_future_syms = section_objs(hdr, sechdrs, secstrings, "__ksymtab_gpl_future", sizeof(*mod->gpl_future_syms), &mod->num_gpl_future_syms); mod->gpl_future_crcs = section_addr(hdr, sechdrs, secstrings, "__kcrctab_gpl_future"); #ifdef CONFIG_UNUSED_SYMBOLS mod->unused_syms = section_objs(hdr, sechdrs, secstrings, "__ksymtab_unused", sizeof(*mod->unused_syms), &mod->num_unused_syms); mod->unused_crcs = section_addr(hdr, sechdrs, secstrings, "__kcrctab_unused"); mod->unused_gpl_syms = section_objs(hdr, sechdrs, secstrings, "__ksymtab_unused_gpl", sizeof(*mod->unused_gpl_syms), &mod->num_unused_gpl_syms); mod->unused_gpl_crcs = section_addr(hdr, sechdrs, secstrings, "__kcrctab_unused_gpl"); #endif #ifdef CONFIG_MARKERS mod->markers = section_objs(hdr, sechdrs, secstrings, "__markers", sizeof(*mod->markers), &mod->num_markers); #endif #ifdef CONFIG_TRACEPOINTS mod->tracepoints = section_objs(hdr, sechdrs, secstrings, "__tracepoints", sizeof(*mod->tracepoints), &mod->num_tracepoints); #endif #ifdef CONFIG_MODVERSIONS if ((mod->num_syms && !mod->crcs) || (mod->num_gpl_syms && !mod->gpl_crcs) || (mod->num_gpl_future_syms && !mod->gpl_future_crcs) #ifdef CONFIG_UNUSED_SYMBOLS || (mod->num_unused_syms && !mod->unused_crcs) || (mod->num_unused_gpl_syms && !mod->unused_gpl_crcs) #endif ) { printk(KERN_WARNING "%s: No versions for exported symbols.\n", mod->name); err = try_to_force_load(mod, "nocrc"); if (err) goto cleanup; } #endif /* Now do relocations. */ for (i = 1; i < hdr->e_shnum; i++) { const char *strtab = (char *)sechdrs[strindex].sh_addr; unsigned int info = sechdrs[i].sh_info; /* Not a valid relocation section? */ if (info >= hdr->e_shnum) continue; /* Don't bother with non-allocated sections */ if (!(sechdrs[info].sh_flags & SHF_ALLOC)) continue; if (sechdrs[i].sh_type == SHT_REL) err = apply_relocate(sechdrs, strtab, symindex, i,mod); else if (sechdrs[i].sh_type == SHT_RELA) err = apply_relocate_add(sechdrs, strtab, symindex, i, mod); if (err < 0) goto cleanup; } /* Find duplicate symbols */ err = verify_export_symbols(mod); if (err < 0) goto cleanup; /* Set up and sort exception table */ mod->extable = section_objs(hdr, sechdrs, secstrings, "__ex_table", sizeof(*mod->extable), &mod->num_exentries); sort_extable(mod->extable, mod->extable + mod->num_exentries); /* Finally, copy percpu area over. */ percpu_modcopy(mod->percpu, (void *)sechdrs[pcpuindex].sh_addr, sechdrs[pcpuindex].sh_size); add_kallsyms(mod, sechdrs, symindex, strindex, secstrings); if (!mod->taints) { struct mod_debug *debug; unsigned int num_debug; debug = section_objs(hdr, sechdrs, secstrings, "__verbose", sizeof(*debug), &num_debug); dynamic_printk_setup(debug, num_debug); } /* sechdrs[0].sh_size is always zero */ mseg = section_objs(hdr, sechdrs, secstrings, "__mcount_loc", sizeof(*mseg), &num_mcount); ftrace_init_module(mod, mseg, mseg + num_mcount); err = module_finalize(hdr, sechdrs, mod); if (err < 0) goto cleanup; /* flush the icache in correct context */ old_fs = get_fs(); set_fs(KERNEL_DS); /* * Flush the instruction cache, since we've played with text. * Do it before processing of module parameters, so the module * can provide parameter accessor functions of its own. */ if (mod->module_init) flush_icache_range((unsigned long)mod->module_init, (unsigned long)mod->module_init + mod->init_size); flush_icache_range((unsigned long)mod->module_core, (unsigned long)mod->module_core + mod->core_size); set_fs(old_fs); mod->args = args; if (section_addr(hdr, sechdrs, secstrings, "__obsparm")) 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. * lockdep/oops can run asynchronous, so use the RCU list insertion * function to insert in a way safe to concurrent readers. * The mutex protects against concurrent writers. */ list_add_rcu(&mod->list, &modules); err = parse_args(mod->name, mod->args, kp, num_kp, NULL); if (err < 0) goto unlink; err = mod_sysfs_setup(mod, kp, num_kp); if (err < 0) goto unlink; add_sect_attrs(mod, hdr->e_shnum, secstrings, sechdrs); add_notes_attrs(mod, hdr->e_shnum, secstrings, sechdrs); /* Size of section 0 is 0, so this works well if no unwind info. */ mod->unwind_info = unwind_add_table(mod, (void *)sechdrs[unwindex].sh_addr, sechdrs[unwindex].sh_size); /* Get rid of temporary copy */ vfree(hdr); /* Done! */ return mod; unlink: stop_machine(__unlink_module, mod, NULL); module_arch_cleanup(mod); cleanup: kobject_del(&mod->mkobj.kobj); kobject_put(&mod->mkobj.kobj); ftrace_release(mod->module_core, mod->core_size); free_unload: module_unload_free(mod); module_free(mod, mod->module_init); free_core: module_free(mod, mod->module_core); free_percpu: if (percpu) percpu_modfree(percpu); free_mod: kfree(args); free_hdr: vfree(hdr); return ERR_PTR(err); truncated: printk(KERN_ERR "Module len %lu truncated\n", len); err = -ENOEXEC; goto free_hdr; } /* This is where the real work happens */ asmlinkage long sys_init_module(void __user *umod, unsigned long len, const char __user *uargs) { struct module *mod; int ret = 0; /* Must have permission */ if (!capable(CAP_SYS_MODULE)) return -EPERM; /* Only one module load at a time, please */ if (mutex_lock_interruptible(&module_mutex) != 0) return -EINTR; /* Do all the hard work */ mod = load_module(umod, len, uargs); if (IS_ERR(mod)) { mutex_unlock(&module_mutex); return PTR_ERR(mod); } /* Drop lock so they can recurse */ mutex_unlock(&module_mutex); blocking_notifier_call_chain(&module_notify_list, MODULE_STATE_COMING, mod); /* Start the module */ if (mod->init != NULL) ret = do_one_initcall(mod->init); if (ret < 0) { /* Init routine failed: abort. Try to protect us from buggy refcounters. */ mod->state = MODULE_STATE_GOING; synchronize_sched(); module_put(mod); blocking_notifier_call_chain(&module_notify_list, MODULE_STATE_GOING, mod); mutex_lock(&module_mutex); free_module(mod); mutex_unlock(&module_mutex); wake_up(&module_wq); return ret; } if (ret > 0) { printk(KERN_WARNING "%s: '%s'->init suspiciously returned %d, " "it should follow 0/-E convention\n" KERN_WARNING "%s: loading module anyway...\n", __func__, mod->name, ret, __func__); dump_stack(); } /* Now it's a first class citizen! Wake up anyone waiting for it. */ mod->state = MODULE_STATE_LIVE; wake_up(&module_wq); mutex_lock(&module_mutex); /* Drop initial reference. */ module_put(mod); unwind_remove_table(mod->unwind_info, 1); module_free(mod, mod->module_init); mod->module_init = NULL; mod->init_size = 0; mod->init_text_size = 0; mutex_unlock(&module_mutex); return 0; } static inline int within(unsigned long addr, void *start, unsigned long size) { return ((void *)addr >= start && (void *)addr < start + size); } #ifdef CONFIG_KALLSYMS /* * This ignores the intensely annoying "mapping symbols" found * in ARM ELF files: $a, $t and $d. */ static inline int is_arm_mapping_symbol(const char *str) { return str[0] == '$' && strchr("atd", str[1]) && (str[2] == '\0' || str[2] == '.'); } static const char *get_ksymbol(struct module *mod, unsigned long addr, unsigned long *size, unsigned long *offset) { unsigned int i, best = 0; unsigned long nextval; /* At worse, next value is at end of module */ if (within(addr, mod->module_init, mod->init_size)) nextval = (unsigned long)mod->module_init+mod->init_text_size; else nextval = (unsigned long)mod->module_core+mod->core_text_size; /* Scan for closest preceeding symbol, and next symbol. (ELF starts real symbols at 1). */ for (i = 1; i < mod->num_symtab; i++) { if (mod->symtab[i].st_shndx == SHN_UNDEF) continue; /* We ignore unnamed symbols: they're uninformative * and inserted at a whim. */ if (mod->symtab[i].st_value <= addr && mod->symtab[i].st_value > mod->symtab[best].st_value && *(mod->strtab + mod->symtab[i].st_name) != '\0' && !is_arm_mapping_symbol(mod->strtab + mod->symtab[i].st_name)) best = i; if (mod->symtab[i].st_value > addr && mod->symtab[i].st_value < nextval && *(mod->strtab + mod->symtab[i].st_name) != '\0' && !is_arm_mapping_symbol(mod->strtab + mod->symtab[i].st_name)) nextval = mod->symtab[i].st_value; } if (!best) return NULL; if (size) *size = nextval - mod->symtab[best].st_value; if (offset) *offset = addr - mod->symtab[best].st_value; return mod->strtab + mod->symtab[best].st_name; } /* 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, char *namebuf) { struct module *mod; const char *ret = NULL; preempt_disable();


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