diff options
Diffstat (limited to 'kernel/module.c')
| -rw-r--r-- | kernel/module.c | 2108 |
1 files changed, 2108 insertions, 0 deletions
diff --git a/kernel/module.c b/kernel/module.c new file mode 100644 index 000000000000..2dbfa0773faf --- /dev/null +++ b/kernel/module.c @@ -0,0 +1,2108 @@ +/* Rewritten by Rusty Russell, on the backs of many others... + 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/config.h> +#include <linux/module.h> +#include <linux/moduleloader.h> +#include <linux/init.h> +#include <linux/slab.h> +#include <linux/vmalloc.h> +#include <linux/elf.h> +#include <linux/seq_file.h> +#include <linux/syscalls.h> +#include <linux/fcntl.h> +#include <linux/rcupdate.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/stop_machine.h> +#include <linux/device.h> +#include <asm/uaccess.h> +#include <asm/semaphore.h> +#include <asm/cacheflush.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)) + +/* Protects module list */ +static DEFINE_SPINLOCK(modlist_lock); + +/* List of modules, protected by module_mutex AND modlist_lock */ +static DECLARE_MUTEX(module_mutex); +static LIST_HEAD(modules); + +static DECLARE_MUTEX(notify_mutex); +static struct notifier_block * module_notify_list; + +int register_module_notifier(struct notifier_block * nb) +{ + int err; + down(¬ify_mutex); + err = notifier_chain_register(&module_notify_list, nb); + up(¬ify_mutex); + return err; +} +EXPORT_SYMBOL(register_module_notifier); + +int unregister_module_notifier(struct notifier_block * nb) +{ + int err; + down(¬ify_mutex); + err = notifier_chain_unregister(&module_notify_list, nb); + up(¬ify_mutex); + return err; +} +EXPORT_SYMBOL(unregister_module_notifier); + +/* We require a truly strong try_module_get() */ +static inline int strong_try_module_get(struct module *mod) +{ + if (mod && mod->state == MODULE_STATE_COMING) + return 0; + return try_module_get(mod); +} + +/* A thread that wants to hold a reference to a module only while it + * is running can call ths 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; +} + +/* 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 unsigned long __start___kcrctab[]; +extern const unsigned long __start___kcrctab_gpl[]; + +#ifndef CONFIG_MODVERSIONS +#define symversion(base, idx) NULL +#else +#define symversion(base, idx) ((base) ? ((base) + (idx)) : NULL) +#endif + +/* Find a symbol, return value, crc and module which owns it */ +static unsigned long __find_symbol(const char *name, + struct module **owner, + const unsigned long **crc, + int gplok) +{ + struct module *mod; + unsigned int i; + + /* Core kernel first. */ + *owner = NULL; + for (i = 0; __start___ksymtab+i < __stop___ksymtab; i++) { + if (strcmp(__start___ksymtab[i].name, name) == 0) { + *crc = symversion(__start___kcrctab, i); + return __start___ksymtab[i].value; + } + } + if (gplok) { + for (i = 0; __start___ksymtab_gpl+i<__stop___ksymtab_gpl; i++) + if (strcmp(__start___ksymtab_gpl[i].name, name) == 0) { + *crc = symversion(__start___kcrctab_gpl, i); + return __start___ksymtab_gpl[i].value; + } + } + + /* Now try modules. */ + list_for_each_entry(mod, &modules, list) { + *owner = mod; + for (i = 0; i < mod->num_syms; i++) + if (strcmp(mod->syms[i].name, name) == 0) { + *crc = symversion(mod->crcs, i); + return mod->syms[i].value; + } + + if (gplok) { + for (i = 0; i < mod->num_gpl_syms; i++) { + if (strcmp(mod->gpl_syms[i].name, name) == 0) { + *crc = symversion(mod->gpl_crcs, i); + return mod->gpl_syms[i].value; + } + } + } + } + DEBUGP("Failed to find symbol %s\n", name); + return 0; +} + +/* Find a symbol in this elf symbol table */ +static unsigned long find_local_symbol(Elf_Shdr *sechdrs, + unsigned int symindex, + const char *strtab, + const char *name) +{ + unsigned int i; + Elf_Sym *sym = (void *)sechdrs[symindex].sh_addr; + + /* Search (defined) internal symbols first. */ + for (i = 1; i < sechdrs[symindex].sh_size/sizeof(*sym); i++) { + if (sym[i].st_shndx != SHN_UNDEF + && strcmp(name, strtab + sym[i].st_name) == 0) + return sym[i].st_value; + } + return 0; +} + +/* 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 = kmalloc(sizeof(new[0]) * pcpu_num_allocated*2, + GFP_KERNEL); + if (!new) + return 0; + + memcpy(new, pcpu_size, sizeof(new[0])*pcpu_num_allocated); + pcpu_num_allocated *= 2; + kfree(pcpu_size); + 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; +} + +/* Created by linker magic */ +extern char __per_cpu_start[], __per_cpu_end[]; + +static void *percpu_modalloc(unsigned long size, unsigned long align) +{ + unsigned long extra; + unsigned int i; + void *ptr; + + BUG_ON(align > SMP_CACHE_BYTES); + + 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 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] = -ALIGN(__per_cpu_end-__per_cpu_start, SMP_CACHE_BYTES); + /* 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) +{ + 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 */ + +#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[_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; + if (b == NULL || already_uses(a, b)) return 1; + + if (!strong_try_module_get(b)) + 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); + 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); + /* There can be at most one match. */ + break; + } + } + } +} + +#ifdef CONFIG_MODULE_FORCE_UNLOAD +static inline int try_force(unsigned int flags) +{ + int ret = (flags & O_TRUNC); + if (ret) + tainted |= TAINT_FORCED_MODULE; + return ret; +} +#else +static inline int try_force(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 are told to block. */ + if ((sref->flags & O_NONBLOCK) && module_refcount(sref->mod) != 0) { + if (!(*sref->forced = try_force(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) +{ + struct stopref sref = { mod, flags, forced }; + + return stop_machine_run(__try_stop_module, &sref, NR_CPUS); +} + +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, drop the semaphore first */ + up(&module_mutex); + for (;;) { + DEBUGP("Looking at refcount...\n"); + set_current_state(TASK_UNINTERRUPTIBLE); + if (module_refcount(mod) == 0) + break; + schedule(); + } + current->state = TASK_RUNNING; + down(&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 (down_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 != NULL && mod->exit == NULL) + || mod->unsafe) { + forced = try_force(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); + + /* Final destruction now noone is using it. */ + if (mod->exit != NULL) { + up(&module_mutex); + mod->exit(); + down(&module_mutex); + } + free_module(mod); + + out: + up(&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->unsafe) { + printed_something = 1; + seq_printf(m, "[unsafe],"); + } + + 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; + unsigned long flags; + const unsigned long *crc; + + spin_lock_irqsave(&modlist_lock, flags); + if (!__find_symbol(symbol, &owner, &crc, 1)) + BUG(); + module_put(owner); + spin_unlock_irqrestore(&modlist_lock, flags); +} +EXPORT_SYMBOL(__symbol_put); + +void symbol_put_addr(void *addr) +{ + unsigned long flags; + + spin_lock_irqsave(&modlist_lock, flags); + if (!kernel_text_address((unsigned long)addr)) + BUG(); + + module_put(module_text_address((unsigned long)addr)); + spin_unlock_irqrestore(&modlist_lock, flags); +} +EXPORT_SYMBOL_GPL(symbol_put_addr); + +static ssize_t show_refcnt(struct module_attribute *mattr, + struct module *mod, char *buffer) +{ + /* sysfs holds a reference */ + return sprintf(buffer, "%u\n", module_refcount(mod)-1); +} + +static struct module_attribute refcnt = { + .attr = { .name = "refcnt", .mode = 0444, .owner = THIS_MODULE }, + .show = show_refcnt, +}; + +#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); +} + +static inline void module_unload_init(struct module *mod) +{ +} +#endif /* CONFIG_MODULE_UNLOAD */ + +#ifdef CONFIG_OBSOLETE_MODPARM +/* Bounds checking done below */ +static int obsparm_copy_string(const char *val, struct kernel_param *kp) +{ + strcpy(kp->arg, val); + return 0; +} + +int set_obsolete(const char *val, struct kernel_param *kp) +{ + unsigned int min, max; + unsigned int size, maxsize; + int dummy; + char *endp; + const char *p; + struct obsolete_modparm *obsparm = kp->arg; + + if (!val) { + printk(KERN_ERR "Parameter %s needs an argument\n", kp->name); + return -EINVAL; + } + + /* type is: [min[-max]]{b,h,i,l,s} */ + p = obsparm->type; + min = simple_strtol(p, &endp, 10); + if (endp == obsparm->type) + min = max = 1; + else if (*endp == '-') { + p = endp+1; + max = simple_strtol(p, &endp, 10); + } else + max = min; + switch (*endp) { + case 'b': + return param_array(kp->name, val, min, max, obsparm->addr, + 1, param_set_byte, &dummy); + case 'h': + return param_array(kp->name, val, min, max, obsparm->addr, + sizeof(short), param_set_short, &dummy); + case 'i': + return param_array(kp->name, val, min, max, obsparm->addr, + sizeof(int), param_set_int, &dummy); + case 'l': + return param_array(kp->name, val, min, max, obsparm->addr, + sizeof(long), param_set_long, &dummy); + case 's': + return param_array(kp->name, val, min, max, obsparm->addr, + sizeof(char *), param_set_charp, &dummy); + + case 'c': + /* Undocumented: 1-5c50 means 1-5 strings of up to 49 chars, + and the decl is "char xxx[5][50];" */ + p = endp+1; + maxsize = simple_strtol(p, &endp, 10); + /* We check lengths here (yes, this is a hack). */ + p = val; + while (p[size = strcspn(p, ",")]) { + if (size >= maxsize) + goto oversize; + p += size+1; + } + if (size >= maxsize) + goto oversize; + return param_array(kp->name, val, min, max, obsparm->addr, + maxsize, obsparm_copy_string, &dummy); + } + printk(KERN_ERR "Unknown obsolete parameter type %s\n", obsparm->type); + return -EINVAL; + oversize: + printk(KERN_ERR + "Parameter %s doesn't fit in %u chars.\n", kp->name, maxsize); + return -EINVAL; +} + +static int obsolete_params(const char *name, + char *args, + struct obsolete_modparm obsparm[], + unsigned int num, + Elf_Shdr *sechdrs, + unsigned int symindex, + const char *strtab) +{ + struct kernel_param *kp; + unsigned int i; + int ret; + + kp = kmalloc(sizeof(kp[0]) * num, GFP_KERNEL); + if (!kp) + return -ENOMEM; + + for (i = 0; i < num; i++) { + char sym_name[128 + sizeof(MODULE_SYMBOL_PREFIX)]; + + snprintf(sym_name, sizeof(sym_name), "%s%s", + MODULE_SYMBOL_PREFIX, obsparm[i].name); + + kp[i].name = obsparm[i].name; + kp[i].perm = 000; + kp[i].set = set_obsolete; + kp[i].get = NULL; + obsparm[i].addr + = (void *)find_local_symbol(sechdrs, symindex, strtab, + sym_name); + if (!obsparm[i].addr) { + printk("%s: falsely claims to have parameter %s\n", + name, obsparm[i].name); + ret = -EINVAL; + goto out; + } + kp[i].arg = &obsparm[i]; + } + + ret = parse_args(name, args, kp, num, NULL); + out: + kfree(kp); + return ret; +} +#else +static int obsolete_params(const char *name, + char *args, + struct obsolete_modparm obsparm[], + unsigned int num, + Elf_Shdr *sechdrs, + unsigned int symindex, + const char *strtab) +{ + if (num != 0) + printk(KERN_WARNING "%s: Ignoring obsolete parameters\n", + name); + return 0; +} +#endif /* CONFIG_OBSOLETE_MODPARM */ + +static const char vermagic[] = VERMAGIC_STRING; + +#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; + + 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; + printk("%s: disagrees about version of symbol %s\n", + mod->name, symname); + DEBUGP("Found checksum %lX vs module %lX\n", + *crc, versions[i].crc); + return 0; + } + /* Not in module's version table. OK, but that taints the kernel. */ + if (!(tainted & TAINT_FORCED_MODULE)) { + printk("%s: no version for \"%s\" found: kernel tainted.\n", + mod->name, symname); + tainted |= TAINT_FORCED_MODULE; + } + return 1; +} + +static inline int check_modstruct_version(Elf_Shdr *sechdrs, + unsigned int versindex, + struct module *mod) +{ + const unsigned long *crc; + struct module *owner; + + if (!__find_symbol("struct_module", &owner, &crc, 1)) + BUG(); + return check_version(sechdrs, versindex, "struct_module", mod, + crc); +} + +/* First part is kernel version, which we ignore. */ +static inline int same_magic(const char *amagic, const char *bmagic) +{ + 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) +{ + 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; + + spin_lock_irq(&modlist_lock); + ret = __find_symbol(name, &owner, &crc, mod->license_gplok); + if (ret) { + /* use_module can fail due to OOM, or module unloading */ + if (!check_version(sechdrs, versindex, name, mod, crc) || + !use_module(mod, owner)) + ret = 0; + } + spin_unlock_irq(&modlist_lock); + return ret; +} + + +/* + * /sys/module/foo/sections stuff + * J. Corbet <corbet@lwn.net> + */ +#ifdef CONFIG_KALLSYMS +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 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]); + if (! (sect_attrs = kmalloc(size[0] + size[1], GFP_KERNEL))) + return; + + /* Setup section attributes. */ + sect_attrs->grp.name = "sections"; + sect_attrs->grp.attrs = (void *)sect_attrs + size[0]; + + sattr = §_attrs->attrs[0]; + gattr = §_attrs->grp.attrs[0]; + for (i = 0; i < nsect; i++) { + if (! (sechdrs[i].sh_flags & SHF_ALLOC)) + continue; + sattr->address = sechdrs[i].sh_addr; + strlcpy(sattr->name, secstrings + sechdrs[i].sh_name, + MODULE_SECT_NAME_LEN); + sattr->mattr.show = module_sect_show; + sattr->mattr.store = NULL; + sattr->mattr.attr.name = sattr->name; + sattr->mattr.attr.owner = mod; + sattr->mattr.attr.mode = S_IRUGO; + *(gattr++) = &(sattr++)->mattr.attr; + } + *gattr = NULL; + + if (sysfs_create_group(&mod->mkobj.kobj, §_attrs->grp)) + goto out; + + mod->sect_attrs = sect_attrs; + return; + out: + kfree(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. */ + kfree(mod->sect_attrs); + mod->sect_attrs = NULL; + } +} + + +#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) +{ +} +#endif /* CONFIG_KALLSYMS */ + + +#ifdef CONFIG_MODULE_UNLOAD +static inline int module_add_refcnt_attr(struct module *mod) +{ + return sysfs_create_file(&mod->mkobj.kobj, &refcnt.attr); +} +static void module_remove_refcnt_attr(struct module *mod) +{ + return sysfs_remove_file(&mod->mkobj.kobj, &refcnt.attr); +} +#else +static inline int module_add_refcnt_attr(struct module *mod) +{ + return 0; +} +static void module_remove_refcnt_attr(struct module *mod) +{ +} +#endif + + +static int mod_sysfs_setup(struct module *mod, + struct kernel_param *kparam, + unsigned int num_params) +{ + int err; + + memset(&mod->mkobj.kobj, 0, sizeof(mod->mkobj.kobj)); + err = kobject_set_name(&mod->mkobj.kobj, "%s", mod->name); + if (err) + goto out; + kobj_set_kset_s(&mod->mkobj, module_subsys); + mod->mkobj.mod = mod; + err = kobject_register(&mod->mkobj.kobj); + if (err) + goto out; + + err = module_add_refcnt_attr(mod); + if (err) + goto out_unreg; + + err = module_param_sysfs_setup(mod, kparam, num_params); + if (err) + goto out_unreg; + + return 0; + +out_unreg: + kobject_unregister(&mod->mkobj.kobj); +out: + return err; +} + +static void mod_kobject_remove(struct module *mod) +{ + module_remove_refcnt_attr(mod); + module_param_sysfs_remove(mod); + + kobject_unregister(&mod->mkobj.kobj); +} + +/* + * 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_run(__unlink_module, mod, NR_CPUS); + remove_sect_attrs(mod); + mod_kobject_remove(mod); + + /* Arch-specific cleanup. */ + module_arch_cleanup(mod); + + /* Module unload stuff */ + module_unload_free(mod); + + /* This may be NULL, but that's OK */ + module_free(mod, mod->module_init); + kfree(mod->args); + if (mod->percpu) + percpu_modfree(mod->percpu); + + /* 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, flags; + const unsigned long *crc; + + spin_lock_irqsave(&modlist_lock, flags); + value = __find_symbol(symbol, &owner, &crc, 1); + if (value && !strong_try_module_get(owner)) + value = 0; + spin_unlock_irqrestore(&modlist_lock, flags); + + return (void *)value; +} +EXPORT_SYMBOL_GPL(__symbol_get); + +/* Change all symbols so that sh_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 (sym[i].st_value != 0) + 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 long *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 inline int license_is_gpl_compatible(const char *license) +{ + return (strcmp(license, "GPL") == 0 + || strcmp(license, "GPL v2") == 0 + || strcmp(license, "GPL and additional rights") == 0 + || strcmp(license, "Dual BSD/GPL") == 0 + || strcmp(license, "Dual MPL/GPL") == 0); +} + +static void set_license(struct module *mod, const char *license) +{ + if (!license) + license = "unspecified"; + + mod->license_gplok = license_is_gpl_compatible(license); + if (!mod->license_gplok && !(tainted & TAINT_PROPRIETARY_MODULE)) { + printk(KERN_WARNING "%s: module license '%s' taints kernel.\n", + mod->name, license); + tainted |= 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; +} + +#ifdef CONFIG_KALLSYMS +int is_exported(const char *name, const struct module *mod) +{ + unsigned int i; + + if (!mod) { + for (i = 0; __start___ksymtab+i < __stop___ksymtab; i++) + if (strcmp(__start___ksymtab[i].name, name) == 0) + return 1; + return 0; + } + for (i = 0; i < mod->num_syms; i++) + if (strcmp(mod->syms[i].name, name) == 0) + return 1; + 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 */ + +/* Allocate and load the module: note that size of section 0 is always + zero, and we rely on this for optional sections. */ +static 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; + unsigned int i, symindex = 0, strindex = 0, setupindex, exindex, + exportindex, modindex, obsparmindex, infoindex, gplindex, + crcindex, gplcrcindex, versindex, pcpuindex; + long arglen; + struct module *mod; + long err = 0; + void *percpu = NULL, *ptr = NULL; /* Stops spurious gcc warning */ + struct exception_table_entry *extable; + + 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, 4) != 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; + } + 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; + } + + /* Optional sections */ + exportindex = find_sec(hdr, sechdrs, secstrings, "__ksymtab"); + gplindex = find_sec(hdr, sechdrs, secstrings, "__ksymtab_gpl"); + crcindex = find_sec(hdr, sechdrs, secstrings, "__kcrctab"); + gplcrcindex = find_sec(hdr, sechdrs, secstrings, "__kcrctab_gpl"); + setupindex = find_sec(hdr, sechdrs, secstrings, "__param"); + exindex = find_sec(hdr, sechdrs, secstrings, "__ex_table"); + obsparmindex = find_sec(hdr, sechdrs, secstrings, "__obsparm"); + versindex = find_sec(hdr, sechdrs, secstrings, "__versions"); + infoindex = find_sec(hdr, sechdrs, secstrings, ".modinfo"); + pcpuindex = find_pcpusec(hdr, sechdrs, secstrings); + + /* Don't keep modinfo section */ + sechdrs[infoindex].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 + + /* 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) { + tainted |= TAINT_FORCED_MODULE; + printk(KERN_WARNING "%s: no version magic, tainting kernel.\n", + mod->name); + } else if (!same_magic(modmagic, vermagic)) { + printk(KERN_ERR "%s: version magic '%s' should be '%s'\n", + mod->name, modmagic, vermagic); + err = -ENOEXEC; + goto free_hdr; + } + + /* Now copy in args */ + arglen = strlen_user(uargs); + if (!arglen) { + err = -EFAULT; + goto free_hdr; + } + args = kmalloc(arglen, GFP_KERNEL); + if (!args) { + err = -ENOMEM; + goto free_hdr; + } + if (copy_from_user(args, uargs, arglen) != 0) { + err = -EFAULT; + goto free_mod; + } + + 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); + 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(mod->core_size); + if (!ptr) { + err = -ENOMEM; + goto free_percpu; + } + memset(ptr, 0, mod->core_size); + mod->module_core = ptr; + + ptr = module_alloc(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); + + /* Set up license info based on the info section */ + set_license(mod, get_modinfo(sechdrs, infoindex, "license")); + + /* 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; + + /* Set up EXPORTed & EXPORT_GPLed symbols (section 0 is 0 length) */ + mod->num_syms = sechdrs[exportindex].sh_size / sizeof(*mod->syms); + mod->syms = (void *)sechdrs[exportindex].sh_addr; + if (crcindex) + mod->crcs = (void *)sechdrs[crcindex].sh_addr; + mod->num_gpl_syms = sechdrs[gplindex].sh_size / sizeof(*mod->gpl_syms); + mod->gpl_syms = (void *)sechdrs[gplindex].sh_addr; + if (gplcrcindex) + mod->gpl_crcs = (void *)sechdrs[gplcrcindex].sh_addr; + +#ifdef CONFIG_MODVERSIONS + if ((mod->num_syms && !crcindex) || + (mod->num_gpl_syms && !gplcrcindex)) { + printk(KERN_WARNING "%s: No versions for exported symbols." + " Tainting kernel.\n", mod->name); + tainted |= TAINT_FORCED_MODULE; + } +#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; + } + + /* Set up and sort exception table */ + mod->num_exentries = sechdrs[exindex].sh_size / sizeof(*mod->extable); + mod->extable = extable = (void *)sechdrs[exindex].sh_addr; + sort_extable(extable, 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); + + err = module_finalize(hdr, sechdrs, mod); + if (err < 0) + goto cleanup; + + mod->args = args; + if (obsparmindex) { + err = obsolete_params(mod->name, mod->args, + (struct obsolete_modparm *) + sechdrs[obsparmindex].sh_addr, + sechdrs[obsparmindex].sh_size + / sizeof(struct obsolete_modparm), + sechdrs, symindex, + (char *)sechdrs[strindex].sh_addr); + if (setupindex) + printk(KERN_WARNING "%s: Ignoring new-style " + "parameters in presence of obsolete ones\n", + mod->name); + } else { + /* Size of section 0 is 0, so this works well if no params */ + err = parse_args(mod->name, mod->args, + (struct kernel_param *) + sechdrs[setupindex].sh_addr, + sechdrs[setupindex].sh_size + / sizeof(struct kernel_param), + NULL); + } + if (err < 0) + goto arch_cleanup; + + err = mod_sysfs_setup(mod, + (struct kernel_param *) + sechdrs[setupindex].sh_addr, + sechdrs[setupindex].sh_size + / sizeof(struct kernel_param)); + if (err < 0) + goto arch_cleanup; + add_sect_attrs(mod, hdr->e_shnum, secstrings, sechdrs); + + /* Get rid of temporary copy */ + vfree(hdr); + + /* Done! */ + return mod; + + arch_cleanup: + module_arch_cleanup(mod); + cleanup: + 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); + if (err < 0) return ERR_PTR(err); + else return ptr; + + truncated: + printk(KERN_ERR "Module len %lu truncated\n", len); + err = -ENOEXEC; + 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, + 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 (down_interruptible(&module_mutex) != 0) + return -EINTR; + + /* Do all the hard work */ + mod = load_module(umod, len, uargs); + if (IS_ERR(mod)) { + up(&module_mutex); + return PTR_ERR(mod); + } + + /* Flush the instruction cache, since we've played with text */ + 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); + + /* 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 */ + up(&module_mutex); + + down(¬ify_mutex); + notifier_call_chain(&module_notify_list, MODULE_STATE_COMING, mod); + up(¬ify_mutex); + + /* Start the module */ + if (mod->init != NULL) + ret = mod->init(); + if (ret < 0) { + /* Init routine failed: abort. Try to protect us from + buggy refcounters. */ + mod->state = MODULE_STATE_GOING; + synchronize_kernel(); + if (mod->unsafe) + printk(KERN_ERR "%s: module is now stuck!\n", + mod->name); + else { + module_put(mod); + down(&module_mutex); + free_module(mod); + up(&module_mutex); + } + return ret; + } + + /* Now it's a first class citizen! */ + down(&module_mutex); + mod->state = MODULE_STATE_LIVE; + /* Drop initial reference. */ + module_put(mod); + module_free(mod, mod->module_init); + mod->module_init = NULL; + mod->init_size = 0; + mod->init_text_size = 0; + up(&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; + + *size = nextval - mod->symtab[best].st_value; + *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. + We don't lock, as this is used for oops resolution and races are a + lesser concern. */ +const char *module_address_lookup(unsigned long addr, + unsigned long *size, + unsigned long *offset, + char **modname) +{ + struct module *mod; + + list_for_each_entry(mod, &modules, list) { + if (within(addr, mod->module_init, mod->init_size) + || within(addr, mod->module_core, mod->core_size)) { + *modname = mod->name; + return get_ksymbol(mod, addr, size, offset); + } + } + return NULL; +} + +struct module *module_get_kallsym(unsigned int symnum, + unsigned long *value, + char *type, + char namebuf[128]) +{ + struct module *mod; + + down(&module_mutex); + list_for_each_entry(mod, &modules, list) { + if (symnum < mod->num_symtab) { + *value = mod->symtab[symnum].st_value; + *type = mod->symtab[symnum].st_info; + strncpy(namebuf, + mod->strtab + mod->symtab[symnum].st_name, + 127); + up(&module_mutex); + return mod; + } + symnum -= mod->num_symtab; + } + up(&module_mutex); + return NULL; +} + +static unsigned long mod_find_symname(struct module *mod, const char *name) +{ + unsigned int i; + + for (i = 0; i < mod->num_symtab; i++) + if (strcmp(name, mod->strtab+mod->symtab[i].st_name) == 0) + return mod->symtab[i].st_value; + return 0; +} + +/* Look for this name: can be of form module:name. */ +unsigned long module_kallsyms_lookup_name(const char *name) +{ + struct module *mod; + char *colon; + unsigned long ret = 0; + + /* Don't lock: we're in enough trouble already. */ + if ((colon = strchr(name, ':')) != NULL) { + *colon = '\0'; + if ((mod = find_module(name)) != NULL) + ret = mod_find_symname(mod, colon+1); + *colon = ':'; + } else { + list_for_each_entry(mod, &modules, list) + if ((ret = mod_find_symname(mod, name)) != 0) + break; + } + return ret; +} +#endif /* CONFIG_KALLSYMS */ + +/* Called by the /proc file system to return a list of modules. */ +static void *m_start(struct seq_file *m, loff_t *pos) +{ + struct list_head *i; + loff_t n = 0; + + down(&module_mutex); + list_for_each(i, &modules) { + if (n++ == *pos) + break; + } + if (i == &modules) + return NULL; + return i; +} + +static void *m_next(struct seq_file *m, void *p, loff_t *pos) +{ + struct list_head *i = p; + (*pos)++; + if (i->next == &modules) + return NULL; + return i->next; +} + +static void m_stop(struct seq_file *m, void *p) +{ + up(&module_mutex); +} + +static int m_show(struct seq_file *m, void *p) +{ + struct module *mod = list_entry(p, struct module, list); + seq_printf(m, "%s %lu", + mod->name, mod->init_size + mod->core_size); + print_unload_info(m, mod); + + /* Informative for users. */ + seq_printf(m, " %s", + mod->state == MODULE_STATE_GOING ? "Unloading": + mod->state == MODULE_STATE_COMING ? "Loading": + "Live"); + /* Used by oprofile and other similar tools. */ + seq_printf(m, " 0x%p", mod->module_core); + + seq_printf(m, "\n"); + return 0; +} + +/* Format: modulename size refcount deps address + + Where refcount is a number or -, and deps is a comma-separated list + of depends or -. +*/ +struct seq_operations modules_op = { + .start = m_start, + .next = m_next, + .stop = m_stop, + .show = m_show +}; + +/* Given an address, look for it in the module exception tables. */ +const struct exception_table_entry *search_module_extables(unsigned long addr) +{ + unsigned long flags; + const struct exception_table_entry *e = NULL; + struct module *mod; + + spin_lock_irqsave(&modlist_lock, flags); + list_for_each_entry(mod, &modules, list) { + if (mod->num_exentries == 0) + continue; + + e = search_extable(mod->extable, + mod->extable + mod->num_exentries - 1, + addr); + if (e) + break; + } + spin_unlock_irqrestore(&modlist_lock, flags); + + /* Now, if we found one, we are running inside it now, hence + we cannot unload the module, hence no refcnt needed. */ + return e; +} + +/* Is this a valid kernel address? We don't grab the lock: we are oopsing. */ +struct module *__module_text_address(unsigned long addr) +{ + struct module *mod; + + list_for_each_entry(mod, &modules, list) + if (within(addr, mod->module_init, mod->init_text_size) + || within(addr, mod->module_core, mod->core_text_size)) + return mod; + return NULL; +} + +struct module *module_text_address(unsigned long addr) +{ + struct module *mod; + unsigned long flags; + + spin_lock_irqsave(&modlist_lock, flags); + mod = __module_text_address(addr); + spin_unlock_irqrestore(&modlist_lock, flags); + + return mod; +} + +/* Don't grab lock, we're oopsing. */ +void print_modules(void) +{ + struct module *mod; + + printk("Modules linked in:"); + list_for_each_entry(mod, &modules, list) + printk(" %s", mod->name); + printk("\n"); +} + +void module_add_driver(struct module *mod, struct device_driver *drv) +{ + if (!mod || !drv) + return; + + /* Don't check return code; this call is idempotent */ + sysfs_create_link(&drv->kobj, &mod->mkobj.kobj, "module"); +} +EXPORT_SYMBOL(module_add_driver); + +void module_remove_driver(struct device_driver *drv) +{ + if (!drv) + return; + sysfs_remove_link(&drv->kobj, "module"); +} +EXPORT_SYMBOL(module_remove_driver); + +#ifdef CONFIG_MODVERSIONS +/* Generate the signature for struct module here, too, for modversions. */ +void struct_module(struct module *mod) { return; } +EXPORT_SYMBOL(struct_module); +#endif |
