blob: 2ad1b5239910965deb86f6fb10eda308e4b32e59 [file] [log] [blame]
/*
Copyright (C) 2002 Richard Henderson
Copyright (C) 2001 Rusty Russell, 2002, 2010 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/export.h>
#include <linux/extable.h>
#include <linux/moduleloader.h>
#include <linux/trace_events.h>
#include <linux/init.h>
#include <linux/kallsyms.h>
#include <linux/file.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/security.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/device.h>
#include <linux/string.h>
#include <linux/mutex.h>
#include <linux/rculist.h>
#include <linux/uaccess.h>
#include <asm/cacheflush.h>
#include <linux/set_memory.h>
#include <asm/mmu_context.h>
#include <linux/license.h>
#include <asm/sections.h>
#include <linux/tracepoint.h>
#include <linux/ftrace.h>
#include <linux/livepatch.h>
#include <linux/async.h>
#include <linux/percpu.h>
#include <linux/kmemleak.h>
#include <linux/jump_label.h>
#include <linux/pfn.h>
#include <linux/bsearch.h>
#include <linux/dynamic_debug.h>
#include <linux/audit.h>
#include <uapi/linux/module.h>
#include "module-internal.h"
#define CREATE_TRACE_POINTS
#include <trace/events/module.h>
#ifndef ARCH_SHF_SMALL
#define ARCH_SHF_SMALL 0
#endif
/*
* Modules' sections will be aligned on page boundaries
* to ensure complete separation of code and data, but
* only when CONFIG_STRICT_MODULE_RWX=y
*/
#ifdef CONFIG_STRICT_MODULE_RWX
# define debug_align(X) ALIGN(X, PAGE_SIZE)
#else
# define debug_align(X) (X)
#endif
/* If this is set, the section belongs in the init part of the module */
#define INIT_OFFSET_MASK (1UL << (BITS_PER_LONG-1))
/*
* Mutex protects:
* 1) List of modules (also safely readable with preempt_disable),
* 2) module_use links,
* 3) module_addr_min/module_addr_max.
* (delete and add uses RCU list operations). */
DEFINE_MUTEX(module_mutex);
EXPORT_SYMBOL_GPL(module_mutex);
static LIST_HEAD(modules);
#ifdef CONFIG_MODULES_TREE_LOOKUP
/*
* Use a latched RB-tree for __module_address(); this allows us to use
* RCU-sched lookups of the address from any context.
*
* This is conditional on PERF_EVENTS || TRACING because those can really hit
* __module_address() hard by doing a lot of stack unwinding; potentially from
* NMI context.
*/
static __always_inline unsigned long __mod_tree_val(struct latch_tree_node *n)
{
struct module_layout *layout = container_of(n, struct module_layout, mtn.node);
return (unsigned long)layout->base;
}
static __always_inline unsigned long __mod_tree_size(struct latch_tree_node *n)
{
struct module_layout *layout = container_of(n, struct module_layout, mtn.node);
return (unsigned long)layout->size;
}
static __always_inline bool
mod_tree_less(struct latch_tree_node *a, struct latch_tree_node *b)
{
return __mod_tree_val(a) < __mod_tree_val(b);
}
static __always_inline int
mod_tree_comp(void *key, struct latch_tree_node *n)
{
unsigned long val = (unsigned long)key;
unsigned long start, end;
start = __mod_tree_val(n);
if (val < start)
return -1;
end = start + __mod_tree_size(n);
if (val >= end)
return 1;
return 0;
}
static const struct latch_tree_ops mod_tree_ops = {
.less = mod_tree_less,
.comp = mod_tree_comp,
};
static struct mod_tree_root {
struct latch_tree_root root;
unsigned long addr_min;
unsigned long addr_max;
} mod_tree __cacheline_aligned = {
.addr_min = -1UL,
};
#define module_addr_min mod_tree.addr_min
#define module_addr_max mod_tree.addr_max
static noinline void __mod_tree_insert(struct mod_tree_node *node)
{
latch_tree_insert(&node->node, &mod_tree.root, &mod_tree_ops);
}
static void __mod_tree_remove(struct mod_tree_node *node)
{
latch_tree_erase(&node->node, &mod_tree.root, &mod_tree_ops);
}
/*
* These modifications: insert, remove_init and remove; are serialized by the
* module_mutex.
*/
static void mod_tree_insert(struct module *mod)
{
mod->core_layout.mtn.mod = mod;
mod->init_layout.mtn.mod = mod;
__mod_tree_insert(&mod->core_layout.mtn);
if (mod->init_layout.size)
__mod_tree_insert(&mod->init_layout.mtn);
}
static void mod_tree_remove_init(struct module *mod)
{
if (mod->init_layout.size)
__mod_tree_remove(&mod->init_layout.mtn);
}
static void mod_tree_remove(struct module *mod)
{
__mod_tree_remove(&mod->core_layout.mtn);
mod_tree_remove_init(mod);
}
static struct module *mod_find(unsigned long addr)
{
struct latch_tree_node *ltn;
ltn = latch_tree_find((void *)addr, &mod_tree.root, &mod_tree_ops);
if (!ltn)
return NULL;
return container_of(ltn, struct mod_tree_node, node)->mod;
}
#else /* MODULES_TREE_LOOKUP */
static unsigned long module_addr_min = -1UL, module_addr_max = 0;
static void mod_tree_insert(struct module *mod) { }
static void mod_tree_remove_init(struct module *mod) { }
static void mod_tree_remove(struct module *mod) { }
static struct module *mod_find(unsigned long addr)
{
struct module *mod;
list_for_each_entry_rcu(mod, &modules, list) {
if (within_module(addr, mod))
return mod;
}
return NULL;
}
#endif /* MODULES_TREE_LOOKUP */
/*
* Bounds of module text, for speeding up __module_address.
* Protected by module_mutex.
*/
static void __mod_update_bounds(void *base, unsigned int size)
{
unsigned long min = (unsigned long)base;
unsigned long max = min + size;
if (min < module_addr_min)
module_addr_min = min;
if (max > module_addr_max)
module_addr_max = max;
}
static void mod_update_bounds(struct module *mod)
{
__mod_update_bounds(mod->core_layout.base, mod->core_layout.size);
if (mod->init_layout.size)
__mod_update_bounds(mod->init_layout.base, mod->init_layout.size);
}
#ifdef CONFIG_KGDB_KDB
struct list_head *kdb_modules = &modules; /* kdb needs the list of modules */
#endif /* CONFIG_KGDB_KDB */
static void module_assert_mutex(void)
{
lockdep_assert_held(&module_mutex);
}
static void module_assert_mutex_or_preempt(void)
{
#ifdef CONFIG_LOCKDEP
if (unlikely(!debug_locks))
return;
WARN_ON_ONCE(!rcu_read_lock_sched_held() &&
!lockdep_is_held(&module_mutex));
#endif
}
static bool sig_enforce = IS_ENABLED(CONFIG_MODULE_SIG_FORCE);
module_param(sig_enforce, bool_enable_only, 0644);
/*
* Export sig_enforce kernel cmdline parameter to allow other subsystems rely
* on that instead of directly to CONFIG_MODULE_SIG_FORCE config.
*/
bool is_module_sig_enforced(void)
{
return sig_enforce;
}
EXPORT_SYMBOL(is_module_sig_enforced);
/* Block module loading/unloading? */
int modules_disabled = 0;
core_param(nomodule, modules_disabled, bint, 0);
/* Waiting for a module to finish initializing? */
static DECLARE_WAIT_QUEUE_HEAD(module_wq);
static BLOCKING_NOTIFIER_HEAD(module_notify_list);
int register_module_notifier(struct notifier_block *nb)
{
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 success.
* Otherwise an error is returned due to ongoing or failed
* initialization etc.
*/
static inline int strong_try_module_get(struct module *mod)
{
BUG_ON(mod && mod->state == MODULE_STATE_UNFORMED);
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,
enum lockdep_ok lockdep_ok)
{
add_taint(flag, lockdep_ok);
set_bit(flag, &mod->taints);
}
/*
* 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 __noreturn __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(const struct load_info *info, const char *name)
{
unsigned int i;
for (i = 1; i < info->hdr->e_shnum; i++) {
Elf_Shdr *shdr = &info->sechdrs[i];
/* Alloc bit cleared means "ignore it." */
if ((shdr->sh_flags & SHF_ALLOC)
&& strcmp(info->secstrings + shdr->sh_name, name) == 0)
return i;
}
return 0;
}
/* Find a module section, or NULL. */
static void *section_addr(const struct load_info *info, const char *name)
{
/* Section 0 has sh_addr 0. */
return (void *)info->sechdrs[find_sec(info, name)].sh_addr;
}
/* Find a module section, or NULL. Fill in number of "objects" in section. */
static void *section_objs(const struct load_info *info,
const char *name,
size_t object_size,
unsigned int *num)
{
unsigned int sec = find_sec(info, name);
/* Section 0 has sh_addr 0 and sh_size 0. */
*num = info->sechdrs[sec].sh_size / object_size;
return (void *)info->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 s32 __start___kcrctab[];
extern const s32 __start___kcrctab_gpl[];
extern const s32 __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 s32 __start___kcrctab_unused[];
extern const s32 __start___kcrctab_unused_gpl[];
#endif
#ifndef CONFIG_MODVERSIONS
#define symversion(base, idx) NULL
#else
#define symversion(base, idx) ((base != NULL) ? ((base) + (idx)) : NULL)
#endif
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,
void *data),
void *data)
{
unsigned int j;
for (j = 0; j < arrsize; j++) {
if (fn(&arr[j], owner, data))
return true;
}
return false;
}
/* Returns true as soon as fn returns true, otherwise false. */
bool each_symbol_section(bool (*fn)(const struct symsearch *arr,
struct module *owner,
void *data),
void *data)
{
struct module *mod;
static 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
};
module_assert_mutex_or_preempt();
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 (mod->state == MODULE_STATE_UNFORMED)
continue;
if (each_symbol_in_section(arr, ARRAY_SIZE(arr), mod, fn, data))
return true;
}
return false;
}
EXPORT_SYMBOL_GPL(each_symbol_section);
struct find_symbol_arg {
/* Input */
const char *name;
bool gplok;
bool warn;
/* Output */
struct module *owner;
const s32 *crc;
const struct kernel_symbol *sym;
};
static bool check_exported_symbol(const struct symsearch *syms,
struct module *owner,
unsigned int symnum, void *data)
{
struct find_symbol_arg *fsa = data;
if (!fsa->gplok) {
if (syms->licence == GPL_ONLY)
return false;
if (syms->licence == WILL_BE_GPL_ONLY && fsa->warn) {
pr_warn("Symbol %s is being used by a non-GPL module, "
"which will not be allowed in the future\n",
fsa->name);
}
}
#ifdef CONFIG_UNUSED_SYMBOLS
if (syms->unused && fsa->warn) {
pr_warn("Symbol %s is marked as UNUSED, however this module is "
"using it.\n", fsa->name);
pr_warn("This symbol will go away in the future.\n");
pr_warn("Please evaluate if this is the right api to use and "
"if it really is, submit a report to the linux kernel "
"mailing list together with submitting your code for "
"inclusion.\n");
}
#endif
fsa->owner = owner;
fsa->crc = symversion(syms->crcs, symnum);
fsa->sym = &syms->start[symnum];
return true;
}
static unsigned long kernel_symbol_value(const struct kernel_symbol *sym)
{
#ifdef CONFIG_HAVE_ARCH_PREL32_RELOCATIONS
return (unsigned long)offset_to_ptr(&sym->value_offset);
#else
return sym->value;
#endif
}
static const char *kernel_symbol_name(const struct kernel_symbol *sym)
{
#ifdef CONFIG_HAVE_ARCH_PREL32_RELOCATIONS
return offset_to_ptr(&sym->name_offset);
#else
return sym->name;
#endif
}
static int cmp_name(const void *va, const void *vb)
{
const char *a;
const struct kernel_symbol *b;
a = va; b = vb;
return strcmp(a, kernel_symbol_name(b));
}
static bool find_exported_symbol_in_section(const struct symsearch *syms,
struct module *owner,
void *data)
{
struct find_symbol_arg *fsa = data;
struct kernel_symbol *sym;
sym = bsearch(fsa->name, syms->start, syms->stop - syms->start,
sizeof(struct kernel_symbol), cmp_name);
if (sym != NULL && check_exported_symbol(syms, owner,
sym - syms->start, data))
return true;
return false;
}
/* Find an exported symbol and return it, along with, (optional) crc and
* (optional) module which owns it. Needs preempt disabled or module_mutex. */
const struct kernel_symbol *find_symbol(const char *name,
struct module **owner,
const s32 **crc,
bool gplok,
bool warn)
{
struct find_symbol_arg fsa;
fsa.name = name;
fsa.gplok = gplok;
fsa.warn = warn;
if (each_symbol_section(find_exported_symbol_in_section, &fsa)) {
if (owner)
*owner = fsa.owner;
if (crc)
*crc = fsa.crc;
return fsa.sym;
}
pr_debug("Failed to find symbol %s\n", name);
return NULL;
}
EXPORT_SYMBOL_GPL(find_symbol);
/*
* Search for module by name: must hold module_mutex (or preempt disabled
* for read-only access).
*/
static struct module *find_module_all(const char *name, size_t len,
bool even_unformed)
{
struct module *mod;
module_assert_mutex_or_preempt();
list_for_each_entry_rcu(mod, &modules, list) {
if (!even_unformed && mod->state == MODULE_STATE_UNFORMED)
continue;
if (strlen(mod->name) == len && !memcmp(mod->name, name, len))
return mod;
}
return NULL;
}
struct module *find_module(const char *name)
{
module_assert_mutex();
return find_module_all(name, strlen(name), false);
}
EXPORT_SYMBOL_GPL(find_module);
#ifdef CONFIG_SMP
static inline void __percpu *mod_percpu(struct module *mod)
{
return mod->percpu;
}
static int percpu_modalloc(struct module *mod, struct load_info *info)
{
Elf_Shdr *pcpusec = &info->sechdrs[info->index.pcpu];
unsigned long align = pcpusec->sh_addralign;
if (!pcpusec->sh_size)
return 0;
if (align > PAGE_SIZE) {
pr_warn("%s: per-cpu alignment %li > %li\n",
mod->name, align, PAGE_SIZE);
align = PAGE_SIZE;
}
mod->percpu = __alloc_reserved_percpu(pcpusec->sh_size, align);
if (!mod->percpu) {
pr_warn("%s: Could not allocate %lu bytes percpu data\n",
mod->name, (unsigned long)pcpusec->sh_size);
return -ENOMEM;
}
mod->percpu_size = pcpusec->sh_size;
return 0;
}
static void percpu_modfree(struct module *mod)
{
free_percpu(mod->percpu);
}
static unsigned int find_pcpusec(struct load_info *info)
{
return find_sec(info, ".data..percpu");
}
static void percpu_modcopy(struct module *mod,
const void *from, unsigned long size)
{
int cpu;
for_each_possible_cpu(cpu)
memcpy(per_cpu_ptr(mod->percpu, cpu), from, size);
}
bool __is_module_percpu_address(unsigned long addr, unsigned long *can_addr)
{
struct module *mod;
unsigned int cpu;
preempt_disable();
list_for_each_entry_rcu(mod, &modules, list) {
if (mod->state == MODULE_STATE_UNFORMED)
continue;
if (!mod->percpu_size)
continue;
for_each_possible_cpu(cpu) {
void *start = per_cpu_ptr(mod->percpu, cpu);
void *va = (void *)addr;
if (va >= start && va < start + mod->percpu_size) {
if (can_addr) {
*can_addr = (unsigned long) (va - start);
*can_addr += (unsigned long)
per_cpu_ptr(mod->percpu,
get_boot_cpu_id());
}
preempt_enable();
return true;
}
}
}
preempt_enable();
return false;
}
/**
* is_module_percpu_address - test whether address is from module static percpu
* @addr: address to test
*
* Test whether @addr belongs to module static percpu area.
*
* RETURNS:
* %true if @addr is from module static percpu area
*/
bool is_module_percpu_address(unsigned long addr)
{
return __is_module_percpu_address(addr, NULL);
}
#else /* ... !CONFIG_SMP */
static inline void __percpu *mod_percpu(struct module *mod)
{
return NULL;
}
static int percpu_modalloc(struct module *mod, struct load_info *info)
{
/* UP modules shouldn't have this section: ENOMEM isn't quite right */
if (info->sechdrs[info->index.pcpu].sh_size != 0)
return -ENOMEM;
return 0;
}
static inline void percpu_modfree(struct module *mod)
{
}
static unsigned int find_pcpusec(struct load_info *info)
{
return 0;
}
static inline void percpu_modcopy(struct module *mod,
const void *from, unsigned long size)
{
/* pcpusec should be 0, and size of that section should be 0. */
BUG_ON(size != 0);
}
bool is_module_percpu_address(unsigned long addr)
{
return false;
}
bool __is_module_percpu_address(unsigned long addr, unsigned long *can_addr)
{
return false;
}
#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_kobject *mk, char *buffer) \
{ \
return scnprintf(buffer, PAGE_SIZE, "%s\n", mk->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
EXPORT_TRACEPOINT_SYMBOL(module_get);
/* MODULE_REF_BASE is the base reference count by kmodule loader. */
#define MODULE_REF_BASE 1
/* Init the unload section of the module. */
static int module_unload_init(struct module *mod)
{
/*
* Initialize reference counter to MODULE_REF_BASE.
* refcnt == 0 means module is going.
*/
atomic_set(&mod->refcnt, MODULE_REF_BASE);
INIT_LIST_HEAD(&mod->source_list);
INIT_LIST_HEAD(&mod->target_list);
/* Hold reference count during initialization. */
atomic_inc(&mod->refcnt);
return 0;
}
/* 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->source_list, source_list) {
if (use->source == a) {
pr_debug("%s uses %s!\n", a->name, b->name);
return 1;
}
}
pr_debug("%s does not use %s!\n", a->name, b->name);
return 0;
}
/*
* Module a uses b
* - we add 'a' as a "source", 'b' as a "target" of module use
* - the module_use is added to the list of 'b' sources (so
* 'b' can walk the list to see who sourced them), and of 'a'
* targets (so 'a' can see what modules it targets).
*/
static int add_module_usage(struct module *a, struct module *b)
{
struct module_use *use;
pr_debug("Allocating new usage for %s.\n", a->name);
use = kmalloc(sizeof(*use), GFP_ATOMIC);
if (!use)
return -ENOMEM;
use->source = a;
use->target = b;
list_add(&use->source_list, &b->source_list);
list_add(&use->target_list, &a->target_list);
return 0;
}
/* Module a uses b: caller needs module_mutex() */
int ref_module(struct module *a, struct module *b)
{
int err;
if (b == NULL || already_uses(a, b))
return 0;
/* If module isn't available, we fail. */
err = strong_try_module_get(b);
if (err)
return err;
err = add_module_usage(a, b);
if (err) {
module_put(b);
return err;
}
return 0;
}
EXPORT_SYMBOL_GPL(ref_module);
/* Clear the unload stuff of the module. */
static void module_unload_free(struct module *mod)
{
struct module_use *use, *tmp;
mutex_lock(&module_mutex);
list_for_each_entry_safe(use, tmp, &mod->target_list, target_list) {
struct module *i = use->target;
pr_debug("%s unusing %s\n", mod->name, i->name);
module_put(i);
list_del(&use->source_list);
list_del(&use->target_list);
kfree(use);
}
mutex_unlock(&module_mutex);
}
#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, LOCKDEP_NOW_UNRELIABLE);
return ret;
}
#else
static inline int try_force_unload(unsigned int flags)
{
return 0;
}
#endif /* CONFIG_MODULE_FORCE_UNLOAD */
/* Try to release refcount of module, 0 means success. */
static int try_release_module_ref(struct module *mod)
{
int ret;
/* Try to decrement refcnt which we set at loading */
ret = atomic_sub_return(MODULE_REF_BASE, &mod->refcnt);
BUG_ON(ret < 0);
if (ret)
/* Someone can put this right now, recover with checking */
ret = atomic_add_unless(&mod->refcnt, MODULE_REF_BASE, 0);
return ret;
}
static int try_stop_module(struct module *mod, int flags, int *forced)
{
/* If it's not unused, quit unless we're forcing. */
if (try_release_module_ref(mod) != 0) {
*forced = try_force_unload(flags);
if (!(*forced))
return -EWOULDBLOCK;
}
/* Mark it as dying. */
mod->state = MODULE_STATE_GOING;
return 0;
}
/**
* module_refcount - return the refcount or -1 if unloading
*
* @mod: the module we're checking
*
* Returns:
* -1 if the module is in the process of unloading
* otherwise the number of references in the kernel to the module
*/
int module_refcount(struct module *mod)
{
return atomic_read(&mod->refcnt) - MODULE_REF_BASE;
}
EXPORT_SYMBOL(module_refcount);
/* This exists whether we can unload or not */
static void free_module(struct module *mod);
SYSCALL_DEFINE2(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) || modules_disabled)
return -EPERM;
if (strncpy_from_user(name, name_user, MODULE_NAME_LEN-1) < 0)
return -EFAULT;
name[MODULE_NAME_LEN-1] = '\0';
audit_log_kern_module(name);
if (mutex_lock_interruptible(&module_mutex) != 0)
return -EINTR;
mod = find_module(name);
if (!mod) {
ret = -ENOENT;
goto out;
}
if (!list_empty(&mod->source_list)) {
/* 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 damn the torpedoes */
pr_debug("%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;
}
}
/* Stop the machine so refcounts can't move and disable module. */
ret = try_stop_module(mod, flags, &forced);
if (ret != 0)
goto out;
mutex_unlock(&module_mutex);
/* Final destruction now no one is using it. */
if (mod->exit != NULL)
mod->exit();
blocking_notifier_call_chain(&module_notify_list,
MODULE_STATE_GOING, mod);
klp_module_going(mod);
ftrace_release_mod(mod);
async_synchronize_full();
/* Store the name of the last unloaded module for diagnostic purposes */
strlcpy(last_unloaded_module, mod->name, sizeof(last_unloaded_module));
free_module(mod);
return 0;
out:
mutex_unlock(&module_mutex);
return ret;
}
static inline void print_unload_info(struct seq_file *m, struct module *mod)
{
struct module_use *use;
int printed_something = 0;
seq_printf(m, " %i ", 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->source_list, source_list) {
printed_something = 1;
seq_printf(m, "%s,", use->source->name);
}
if (mod->init != NULL && mod->exit == NULL) {
printed_something = 1;
seq_puts(m, "[permanent],");
}
if (!printed_something)
seq_puts(m, "-");
}
void __symbol_put(const char *symbol)
{
struct module *owner;
preempt_disable();
if (!find_symbol(symbol, &owner, NULL, true, false))
BUG();
module_put(owner);
preempt_enable();
}
EXPORT_SYMBOL(__symbol_put);
/* Note this assumes addr is a function, which it currently always is. */
void symbol_put_addr(void *addr)
{
struct module *modaddr;
unsigned long a = (unsigned long)dereference_function_descriptor(addr);
if (core_kernel_text(a))
return;
/*
* Even though we hold a reference on the module; we still need to
* disable preemption in order to safely traverse the data structure.
*/
preempt_disable();
modaddr = __module_text_address(a);
BUG_ON(!modaddr);
module_put(modaddr);
preempt_enable();
}
EXPORT_SYMBOL_GPL(symbol_put_addr);
static ssize_t show_refcnt(struct module_attribute *mattr,
struct module_kobject *mk, char *buffer)
{
return sprintf(buffer, "%i\n", module_refcount(mk->mod));
}
static struct module_attribute modinfo_refcnt =
__ATTR(refcnt, 0444, show_refcnt, NULL);
void __module_get(struct module *module)
{
if (module) {
preempt_disable();
atomic_inc(&module->refcnt);
trace_module_get(module, _RET_IP_);
preempt_enable();
}
}
EXPORT_SYMBOL(__module_get);
bool try_module_get(struct module *module)
{
bool ret = true;
if (module) {
preempt_disable();
/* Note: here, we can fail to get a reference */
if (likely(module_is_live(module) &&
atomic_inc_not_zero(&module->refcnt) != 0))
trace_module_get(module, _RET_IP_);
else
ret = false;
preempt_enable();
}
return ret;
}
EXPORT_SYMBOL(try_module_get);
void module_put(struct module *module)
{
int ret;
if (module) {
preempt_disable();
ret = atomic_dec_if_positive(&module->refcnt);
WARN_ON(ret < 0); /* Failed to put refcount */
trace_module_put(module, _RET_IP_);
preempt_enable();
}
}
EXPORT_SYMBOL(module_put);
#else /* !CONFIG_MODULE_UNLOAD */
static inline void print_unload_info(struct seq_file *m, struct module *mod)
{
/* We don't know the usage count, or what modules are using. */
seq_puts(m, " - -");
}
static inline void module_unload_free(struct module *mod)
{
}
int ref_module(struct module *a, struct module *b)
{
return strong_try_module_get(b);
}
EXPORT_SYMBOL_GPL(ref_module);
static inline int module_unload_init(struct module *mod)
{
return 0;
}
#endif /* CONFIG_MODULE_UNLOAD */
static size_t module_flags_taint(struct module *mod, char *buf)
{
size_t l = 0;
int i;
for (i = 0; i < TAINT_FLAGS_COUNT; i++) {
if (taint_flags[i].module && test_bit(i, &mod->taints))
buf[l++] = taint_flags[i].c_true;
}
return l;
}
static ssize_t show_initstate(struct module_attribute *mattr,
struct module_kobject *mk, char *buffer)
{
const char *state = "unknown";
switch (mk->mod->state) {
case MODULE_STATE_LIVE:
state = "live";
break;
case MODULE_STATE_COMING:
state = "coming";
break;
case MODULE_STATE_GOING:
state = "going";
break;
default:
BUG();
}
return sprintf(buffer, "%s\n", state);
}
static struct module_attribute modinfo_initstate =
__ATTR(initstate, 0444, show_initstate, NULL);
static ssize_t store_uevent(struct module_attribute *mattr,
struct module_kobject *mk,
const char *buffer, size_t count)
{
int rc;
rc = kobject_synth_uevent(&mk->kobj, buffer, count);
return rc ? rc : count;
}
struct module_attribute module_uevent =
__ATTR(uevent, 0200, NULL, store_uevent);
static ssize_t show_coresize(struct module_attribute *mattr,
struct module_kobject *mk, char *buffer)
{
return sprintf(buffer, "%u\n", mk->mod->core_layout.size);
}
static struct module_attribute modinfo_coresize =
__ATTR(coresize, 0444, show_coresize, NULL);
static ssize_t show_initsize(struct module_attribute *mattr,
struct module_kobject *mk, char *buffer)
{
return sprintf(buffer, "%u\n", mk->mod->init_layout.size);
}
static struct module_attribute modinfo_initsize =
__ATTR(initsize, 0444, show_initsize, NULL);
static ssize_t show_taint(struct module_attribute *mattr,
struct module_kobject *mk, char *buffer)
{
size_t l;
l = module_flags_taint(mk->mod, buffer);
buffer[l++] = '\n';
return l;
}
static struct module_attribute modinfo_taint =
__ATTR(taint, 0444, show_taint, NULL);
static struct module_attribute *modinfo_attrs[] = {
&module_uevent,
&modinfo_version,
&modinfo_srcversion,
&modinfo_initstate,
&modinfo_coresize,
&modinfo_initsize,
&modinfo_taint,
#ifdef CONFIG_MODULE_UNLOAD
&modinfo_refcnt,
#endif
NULL,
};
static const char vermagic[] = VERMAGIC_STRING;
static int try_to_force_load(struct module *mod, const char *reason)
{
#ifdef CONFIG_MODULE_FORCE_LOAD
if (!test_taint(TAINT_FORCED_MODULE))
pr_warn("%s: %s: kernel tainted.\n", mod->name, reason);
add_taint_module(mod, TAINT_FORCED_MODULE, LOCKDEP_NOW_UNRELIABLE);
return 0;
#else
return -ENOEXEC;
#endif
}
#ifdef CONFIG_MODVERSIONS
static u32 resolve_rel_crc(const s32 *crc)
{
return *(u32 *)((void *)crc + *crc);
}
static int check_version(const struct load_info *info,
const char *symname,
struct module *mod,
const s32 *crc)
{
Elf_Shdr *sechdrs = info->sechdrs;
unsigned int versindex = info->index.vers;
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++) {
u32 crcval;
if (strcmp(versions[i].name, symname) != 0)
continue;
if (IS_ENABLED(CONFIG_MODULE_REL_CRCS))
crcval = resolve_rel_crc(crc);
else
crcval = *crc;
if (versions[i].crc == crcval)
return 1;
pr_debug("Found checksum %X vs module %lX\n",
crcval, versions[i].crc);
goto bad_version;
}
/* Broken toolchain. Warn once, then let it go.. */
pr_warn_once("%s: no symbol version for %s\n", info->name, symname);
return 1;
bad_version:
pr_warn("%s: disagrees about version of symbol %s\n",
info->name, symname);
return 0;
}
static inline int check_modstruct_version(const struct load_info *info,
struct module *mod)
{
const s32 *crc;
/*
* Since this should be found in kernel (which can't be removed), no
* locking is necessary -- use preempt_disable() to placate lockdep.
*/
preempt_disable();
if (!find_symbol("module_layout", NULL, &crc, true, false)) {
preempt_enable();
BUG();
}
preempt_enable();
return check_version(info, "module_layout", 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(const struct load_info *info,
const char *symname,
struct module *mod,
const s32 *crc)
{
return 1;
}
static inline int check_modstruct_version(const struct load_info *info,
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. */
static const struct kernel_symbol *resolve_symbol(struct module *mod,
const struct load_info *info,
const char *name,
char ownername[])
{
struct module *owner;
const struct kernel_symbol *sym;
const s32 *crc;
int err;
/*
* The module_mutex should not be a heavily contended lock;
* if we get the occasional sleep here, we'll go an extra iteration
* in the wait_event_interruptible(), which is harmless.
*/
sched_annotate_sleep();
mutex_lock(&module_mutex);
sym = find_symbol(name, &owner, &crc,
!(mod->taints & (1 << TAINT_PROPRIETARY_MODULE)), true);
if (!sym)
goto unlock;
if (!check_version(info, name, mod, crc)) {
sym = ERR_PTR(-EINVAL);
goto getname;
}
err = ref_module(mod, owner);
if (err) {
sym = ERR_PTR(err);
goto getname;
}
getname:
/* We must make copy under the lock if we failed to get ref. */
strncpy(ownername, module_name(owner), MODULE_NAME_LEN);
unlock:
mutex_unlock(&module_mutex);
return sym;
}
static const struct kernel_symbol *
resolve_symbol_wait(struct module *mod,
const struct load_info *info,
const char *name)
{
const struct kernel_symbol *ksym;
char owner[MODULE_NAME_LEN];
if (wait_event_interruptible_timeout(module_wq,
!IS_ERR(ksym = resolve_symbol(mod, info, name, owner))
|| PTR_ERR(ksym) != -EBUSY,
30 * HZ) <= 0) {
pr_warn("%s: gave up waiting for init of module %s.\n",
mod->name, owner);
}
return ksym;
}
/*
* /sys/module/foo/sections stuff
* J. Corbet <corbet@lwn.net>
*/
#ifdef CONFIG_SYSFS
#ifdef CONFIG_KALLSYMS
static inline bool sect_empty(const Elf_Shdr *sect)
{
return !(sect->sh_flags & SHF_ALLOC) || sect->sh_size == 0;
}
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_kobject *mk, char *buf)
{
struct module_sect_attr *sattr =
container_of(mattr, struct module_sect_attr, mattr);
return sprintf(buf, "0x%px\n", kptr_restrict < 2 ?
(void *)sattr->address : NULL);
}
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, const struct load_info *info)
{
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 < info->hdr->e_shnum; i++)
if (!sect_empty(&info->sechdrs[i]))
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 < info->hdr->e_shnum; i++) {
Elf_Shdr *sec = &info->sechdrs[i];
if (sect_empty(sec))
continue;
sattr->address = sec->sh_addr;
sattr->name = kstrdup(info->secstrings + sec->sh_name,
GFP_KERNEL);
if (sattr->name == NULL)
goto out;
sect_attrs->nsections++;
sysfs_attr_init(&sattr->mattr.attr);
sattr->mattr.show = module_sect_show;
sattr->mattr.store = NULL;
sattr->mattr.attr.name = sattr->name;
sattr->mattr.attr.mode = S_IRUSR;
*(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 file *filp, 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, const struct load_info *info)
{
unsigned int notes, loaded, i;
struct module_notes_attrs *notes_attrs;
struct bin_attribute *nattr;
/* failed to create section attributes, so can't create notes */
if (!mod->sect_attrs)
return;
/* Count notes sections and allocate structures. */
notes = 0;
for (i = 0; i < info->hdr->e_shnum; i++)
if (!sect_empty(&info->sechdrs[i]) &&
(info->sechdrs[i].sh_type == SHT_NOTE))
++notes;
if (notes == 0)
return;
notes_attrs = kzalloc(struct_size(notes_attrs, attrs, notes),
GFP_KERNEL);
if (notes_attrs == NULL)
return;
notes_attrs->notes = notes;
nattr = &notes_attrs->attrs[0];
for (loaded = i = 0; i < info->hdr->e_shnum; ++i) {
if (sect_empty(&info->sechdrs[i]))
continue;
if (info->sechdrs[i].sh_type == SHT_NOTE) {
sysfs_bin_attr_init(nattr);
nattr->attr.name = mod->sect_attrs->attrs[loaded].name;
nattr->attr.mode = S_IRUGO;
nattr->size = info->sechdrs[i].sh_size;
nattr->private = (void *) info->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,
const struct load_info *info)
{
}
static inline void remove_sect_attrs(struct module *mod)
{
}
static inline void add_notes_attrs(struct module *mod,
const struct load_info *info)
{
}
static inline void remove_notes_attrs(struct module *mod)
{
}
#endif /* CONFIG_KALLSYMS */
static void del_usage_links(struct module *mod)
{
#ifdef CONFIG_MODULE_UNLOAD
struct module_use *use;
mutex_lock(&module_mutex);
list_for_each_entry(use, &mod->target_list, target_list)
sysfs_remove_link(use->target->holders_dir, mod->name);
mutex_unlock(&module_mutex);
#endif
}
static int add_usage_links(struct module *mod)
{
int ret = 0;
#ifdef CONFIG_MODULE_UNLOAD
struct module_use *use;
mutex_lock(&module_mutex);
list_for_each_entry(use, &mod->target_list, target_list) {
ret = sysfs_create_link(use->target->holders_dir,
&mod->mkobj.kobj, mod->name);
if (ret)
break;
}
mutex_unlock(&module_mutex);
if (ret)
del_usage_links(mod);
#endif
return ret;
}
static 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(mod)) {
memcpy(temp_attr, attr, sizeof(*temp_attr));
sysfs_attr_init(&temp_attr->attr);
error = sysfs_create_file(&mod->mkobj.kobj,
&temp_attr->attr);
++temp_attr;
}
}
return error;
}
static 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);
}
static void mod_kobject_put(struct module *mod)
{
DECLARE_COMPLETION_ONSTACK(c);
mod->mkobj.kobj_completion = &c;
kobject_put(&mod->mkobj.kobj);
wait_for_completion(&c);
}
static int mod_sysfs_init(struct module *mod)
{
int err;
struct kobject *kobj;
if (!module_sysfs_initialized) {
pr_err("%s: module sysfs not initialized\n", mod->name);
err = -EINVAL;
goto out;
}
kobj = kset_find_obj(module_kset, mod->name);
if (kobj) {
pr_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)
mod_kobject_put(mod);
/* delay uevent until full sysfs population */
out:
return err;
}
static int mod_sysfs_setup(struct module *mod,
const struct load_info *info,
struct kernel_param *kparam,
unsigned int num_params)
{
int err;
err = mod_sysfs_init(mod);
if (err)
goto out;
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;
err = add_usage_links(mod);
if (err)
goto out_unreg_modinfo_attrs;
add_sect_attrs(mod, info);
add_notes_attrs(mod, info);
kobject_uevent(&mod->mkobj.kobj, KOBJ_ADD);
return 0;
out_unreg_modinfo_attrs:
module_remove_modinfo_attrs(mod);
out_unreg_param:
module_param_sysfs_remove(mod);
out_unreg_holders:
kobject_put(mod->holders_dir);
out_unreg:
mod_kobject_put(mod);
out:
return err;
}
static void mod_sysfs_fini(struct module *mod)
{
remove_notes_attrs(mod);
remove_sect_attrs(mod);
mod_kobject_put(mod);
}
static void init_param_lock(struct module *mod)
{
mutex_init(&mod->param_lock);
}
#else /* !CONFIG_SYSFS */
static int mod_sysfs_setup(struct module *mod,
const struct load_info *info,
struct kernel_param *kparam,
unsigned int num_params)
{
return 0;
}
static void mod_sysfs_fini(struct module *mod)
{
}
static void module_remove_modinfo_attrs(struct module *mod)
{
}
static void del_usage_links(struct module *mod)
{
}
static void init_param_lock(struct module *mod)
{
}
#endif /* CONFIG_SYSFS */
static void mod_sysfs_teardown(struct module *mod)
{
del_usage_links(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);
}
#ifdef CONFIG_STRICT_MODULE_RWX
/*
* LKM RO/NX protection: protect module's text/ro-data
* from modification and any data from execution.
*
* General layout of module is:
* [text] [read-only-data] [ro-after-init] [writable data]
* text_size -----^ ^ ^ ^
* ro_size ------------------------| | |
* ro_after_init_size -----------------------------| |
* size -----------------------------------------------------------|
*
* These values are always page-aligned (as is base)
*/
static void frob_text(const struct module_layout *layout,
int (*set_memory)(unsigned long start, int num_pages))
{
BUG_ON((unsigned long)layout->base & (PAGE_SIZE-1));
BUG_ON((unsigned long)layout->text_size & (PAGE_SIZE-1));
set_memory((unsigned long)layout->base,
layout->text_size >> PAGE_SHIFT);
}
static void frob_rodata(const struct module_layout *layout,
int (*set_memory)(unsigned long start, int num_pages))
{
BUG_ON((unsigned long)layout->base & (PAGE_SIZE-1));
BUG_ON((unsigned long)layout->text_size & (PAGE_SIZE-1));
BUG_ON((unsigned long)layout->ro_size & (PAGE_SIZE-1));
set_memory((unsigned long)layout->base + layout->text_size,
(layout->ro_size - layout->text_size) >> PAGE_SHIFT);
}
static void frob_ro_after_init(const struct module_layout *layout,
int (*set_memory)(unsigned long start, int num_pages))
{
BUG_ON((unsigned long)layout->base & (PAGE_SIZE-1));
BUG_ON((unsigned long)layout->ro_size & (PAGE_SIZE-1));
BUG_ON((unsigned long)layout->ro_after_init_size & (PAGE_SIZE-1));
set_memory((unsigned long)layout->base + layout->ro_size,
(layout->ro_after_init_size - layout->ro_size) >> PAGE_SHIFT);
}
static void frob_writable_data(const struct module_layout *layout,
int (*set_memory)(unsigned long start, int num_pages))
{
BUG_ON((unsigned long)layout->base & (PAGE_SIZE-1));
BUG_ON((unsigned long)layout->ro_after_init_size & (PAGE_SIZE-1));
BUG_ON((unsigned long)layout->size & (PAGE_SIZE-1));
set_memory((unsigned long)layout->base + layout->ro_after_init_size,
(layout->size - layout->ro_after_init_size) >> PAGE_SHIFT);
}
/* livepatching wants to disable read-only so it can frob module. */
void module_disable_ro(const struct module *mod)
{
if (!rodata_enabled)
return;
frob_text(&mod->core_layout, set_memory_rw);
frob_rodata(&mod->core_layout, set_memory_rw);
frob_ro_after_init(&mod->core_layout, set_memory_rw);
frob_text(&mod->init_layout, set_memory_rw);
frob_rodata(&mod->init_layout, set_memory_rw);
}
void module_enable_ro(const struct module *mod, bool after_init)
{
if (!rodata_enabled)
return;
frob_text(&mod->core_layout, set_memory_ro);
frob_rodata(&mod->core_layout, set_memory_ro);
frob_text(&mod->init_layout, set_memory_ro);
frob_rodata(&mod->init_layout, set_memory_ro);
if (after_init)
frob_ro_after_init(&mod->core_layout, set_memory_ro);
}
static void module_enable_nx(const struct module *mod)
{
frob_rodata(&mod->core_layout, set_memory_nx);
frob_ro_after_init(&mod->core_layout, set_memory_nx);
frob_writable_data(&mod->core_layout, set_memory_nx);
frob_rodata(&mod->init_layout, set_memory_nx);
frob_writable_data(&mod->init_layout, set_memory_nx);
}
static void module_disable_nx(const struct module *mod)
{
frob_rodata(&mod->core_layout, set_memory_x);
frob_ro_after_init(&mod->core_layout, set_memory_x);
frob_writable_data(&mod->core_layout, set_memory_x);
frob_rodata(&mod->init_layout, set_memory_x);
frob_writable_data(&mod->init_layout, set_memory_x);
}
/* Iterate through all modules and set each module's text as RW */
void set_all_modules_text_rw(void)
{
struct module *mod;
if (!rodata_enabled)
return;
mutex_lock(&module_mutex);
list_for_each_entry_rcu(mod, &modules, list) {
if (mod->state == MODULE_STATE_UNFORMED)
continue;
frob_text(&mod->core_layout, set_memory_rw);
frob_text(&mod->init_layout, set_memory_rw);
}
mutex_unlock(&module_mutex);
}
/* Iterate through all modules and set each module's text as RO */
void set_all_modules_text_ro(void)
{
struct module *mod;
if (!rodata_enabled)
return;
mutex_lock(&module_mutex);
list_for_each_entry_rcu(mod, &modules, list) {
/*
* Ignore going modules since it's possible that ro
* protection has already been disabled, otherwise we'll
* run into protection faults at module deallocation.
*/
if (mod->state == MODULE_STATE_UNFORMED ||
mod->state == MODULE_STATE_GOING)
continue;
frob_text(&mod->core_layout, set_memory_ro);
frob_text(&mod->init_layout, set_memory_ro);
}
mutex_unlock(&module_mutex);
}
static void disable_ro_nx(const struct module_layout *layout)
{
if (rodata_enabled) {
frob_text(layout, set_memory_rw);
frob_rodata(layout, set_memory_rw);
frob_ro_after_init(layout, set_memory_rw);
}
frob_rodata(layout, set_memory_x);
frob_ro_after_init(layout, set_memory_x);
frob_writable_data(layout, set_memory_x);
}
#else
static void disable_ro_nx(const struct module_layout *layout) { }
static void module_enable_nx(const struct module *mod) { }
static void module_disable_nx(const struct module *mod) { }
#endif
#ifdef CONFIG_LIVEPATCH
/*
* Persist Elf information about a module. Copy the Elf header,
* section header table, section string table, and symtab section
* index from info to mod->klp_info.
*/
static int copy_module_elf(struct module *mod, struct load_info *info)
{
unsigned int size, symndx;
int ret;
size = sizeof(*mod->klp_info);
mod->klp_info = kmalloc(size, GFP_KERNEL);
if (mod->klp_info == NULL)
return -ENOMEM;
/* Elf header */
size = sizeof(mod->klp_info->hdr);
memcpy(&mod->klp_info->hdr, info->hdr, size);
/* Elf section header table */
size = sizeof(*info->sechdrs) * info->hdr->e_shnum;
mod->klp_info->sechdrs = kmemdup(info->sechdrs, size, GFP_KERNEL);
if (mod->klp_info->sechdrs == NULL) {
ret = -ENOMEM;
goto free_info;
}
/* Elf section name string table */
size = info->sechdrs[info->hdr->e_shstrndx].sh_size;
mod->klp_info->secstrings = kmemdup(info->secstrings, size, GFP_KERNEL);
if (mod->klp_info->secstrings == NULL) {
ret = -ENOMEM;
goto free_sechdrs;
}
/* Elf symbol section index */
symndx = info->index.sym;
mod->klp_info->symndx = symndx;
/*
* For livepatch modules, core_kallsyms.symtab is a complete
* copy of the original symbol table. Adjust sh_addr to point
* to core_kallsyms.symtab since the copy of the symtab in module
* init memory is freed at the end of do_init_module().
*/
mod->klp_info->sechdrs[symndx].sh_addr = \
(unsigned long) mod->core_kallsyms.symtab;
return 0;
free_sechdrs:
kfree(mod->klp_info->sechdrs);
free_info:
kfree(mod->klp_info);
return ret;
}
static void free_module_elf(struct module *mod)
{
kfree(mod->klp_info->sechdrs);
kfree(mod->klp_info->secstrings);
kfree(mod->klp_info);
}
#else /* !CONFIG_LIVEPATCH */
static int copy_module_elf(struct module *mod, struct load_info *info)
{
return 0;
}
static void free_module_elf(struct module *mod)
{
}
#endif /* CONFIG_LIVEPATCH */
void __weak module_memfree(void *module_region)
{
vfree(module_region);
}
void __weak module_arch_cleanup(struct module *mod)
{
}
void __weak module_arch_freeing_init(struct module *mod)
{
}
/* Free a module, remove from lists, etc. */
static void free_module(struct module *mod)
{
trace_module_free(mod);
mod_sysfs_teardown(mod);
/* We leave it in list to prevent duplicate loads, but make sure
* that noone uses it while it's being deconstructed. */
mutex_lock(&module_mutex);
mod->state = MODULE_STATE_UNFORMED;
mutex_unlock(&module_mutex);
/* Remove dynamic debug info */
ddebug_remove_module(mod->name);
/* Arch-specific cleanup. */
module_arch_cleanup(mod);
/* Module unload stuff */
module_unload_free(mod);
/* Free any allocated parameters. */
destroy_params(mod->kp, mod->num_kp);
if (is_livepatch_module(mod))
free_module_elf(mod);
/* Now we can delete it from the lists */
mutex_lock(&module_mutex);
/* Unlink carefully: kallsyms could be walking list. */
list_del_rcu(&mod->list);
mod_tree_remove(mod);
/* Remove this module from bug list, this uses list_del_rcu */
module_bug_cleanup(mod);
/* Wait for RCU-sched synchronizing before releasing mod->list and buglist. */
synchronize_rcu();
mutex_unlock(&module_mutex);
/* This may be empty, but that's OK */
disable_ro_nx(&mod->init_layout);
module_arch_freeing_init(mod);
module_memfree(mod->init_layout.base);
kfree(mod->args);
percpu_modfree(mod);
/* Free lock-classes; relies on the preceding sync_rcu(). */
lockdep_free_key_range(mod->core_layout.base, mod->core_layout.size);
/* Finally, free the core (containing the module structure) */
disable_ro_nx(&mod->core_layout);
module_memfree(mod->core_layout.base);
}
void *__symbol_get(const char *symbol)
{
struct module *owner;
const struct kernel_symbol *sym;
preempt_disable();
sym = find_symbol(symbol, &owner, NULL, true, true);
if (sym && strong_try_module_get(owner))
sym = NULL;
preempt_enable();
return sym ? (void *)kernel_symbol_value(sym) : NULL;
}
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.
*
* You must hold the module_mutex.
*/
static int verify_exported_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 (find_symbol(kernel_symbol_name(s), &owner, NULL,
true, false)) {
pr_err("%s: exports duplicate symbol %s"
" (owned by %s)\n",
mod->name, kernel_symbol_name(s),
module_name(owner));
return -ENOEXEC;
}
}
}
return 0;
}
/* Change all symbols so that st_value encodes the pointer directly. */
static int simplify_symbols(struct module *mod, const struct load_info *info)
{
Elf_Shdr *symsec = &info->sechdrs[info->index.sym];
Elf_Sym *sym = (void *)symsec->sh_addr;
unsigned long secbase;
unsigned int i;
int ret = 0;
const struct kernel_symbol *ksym;
for (i = 1; i < symsec->sh_size / sizeof(Elf_Sym); i++) {
const char *name = info->strtab + sym[i].st_name;
switch (sym[i].st_shndx) {
case SHN_COMMON:
/* Ignore common symbols */
if (!strncmp(name, "__gnu_lto", 9))
break;
/* We compiled with -fno-common. These are not
supposed to happen. */
pr_debug("Common symbol: %s\n", name);
pr_warn("%s: please compile with -fno-common\n",
mod->name);
ret = -ENOEXEC;
break;
case SHN_ABS:
/* Don't need to do anything */
pr_debug("Absolute symbol: 0x%08lx\n",
(long)sym[i].st_value);
break;
case SHN_LIVEPATCH:
/* Livepatch symbols are resolved by livepatch */
break;
case SHN_UNDEF:
ksym = resolve_symbol_wait(mod, info, name);
/* Ok if resolved. */
if (ksym && !IS_ERR(ksym)) {
sym[i].st_value = kernel_symbol_value(ksym);
break;
}
/* Ok if weak. */
if (!ksym && ELF_ST_BIND(sym[i].st_info) == STB_WEAK)
break;
ret = PTR_ERR(ksym) ?: -ENOENT;
pr_warn("%s: Unknown symbol %s (err %d)\n",
mod->name, name, ret);
break;
default:
/* Divert to percpu allocation if a percpu var. */
if (sym[i].st_shndx == info->index.pcpu)
secbase = (unsigned long)mod_percpu(mod);
else
secbase = info->sechdrs[sym[i].st_shndx].sh_addr;
sym[i].st_value += secbase;
break;
}
}
return ret;
}
static int apply_relocations(struct module *mod, const struct load_info *info)
{
unsigned int i;
int err = 0;
/* Now do relocations. */
for (i = 1; i < info->hdr->e_shnum; i++) {
unsigned int infosec = info->sechdrs[i].sh_info;
/* Not a valid relocation section? */
if (infosec >= info->hdr->e_shnum)
continue;
/* Don't bother with non-allocated sections */
if (!(info->sechdrs[infosec].sh_flags & SHF_ALLOC))
continue;
/* Livepatch relocation sections are applied by livepatch */
if (info->sechdrs[i].sh_flags & SHF_RELA_LIVEPATCH)
continue;
if (info->sechdrs[i].sh_type == SHT_REL)
err = apply_relocate(info->sechdrs, info->strtab,
info->index.sym, i, mod);
else if (info->sechdrs[i].sh_type == SHT_RELA)
err = apply_relocate_add(info->sechdrs, info->strtab,
info->index.sym, i, mod);
if (err < 0)
break;
}
return err;
}
/* Additional bytes needed by arch in front of individual sections */
unsigned int __weak arch_mod_section_prepend(struct module *mod,
unsigned int section)
{
/* default implementation just returns zero */
return 0;
}
/* Update size with this section: return offset. */
static long get_offset(struct module *mod, unsigned int *size,
Elf_Shdr *sechdr, unsigned int section)
{
long ret;
*size += arch_mod_section_prepend(mod, section);
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, struct load_info *info)
{
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_RO_AFTER_INIT | SHF_ALLOC, ARCH_SHF_SMALL },
{ SHF_WRITE | SHF_ALLOC, ARCH_SHF_SMALL },
{ ARCH_SHF_SMALL | SHF_ALLOC, 0 }
};
unsigned int m, i;
for (i = 0; i < info->hdr->e_shnum; i++)
info->sechdrs[i].sh_entsize = ~0UL;
pr_debug("Core section allocation order:\n");
for (m = 0; m < ARRAY_SIZE(masks); ++m) {
for (i = 0; i < info->hdr->e_shnum; ++i) {
Elf_Shdr *s = &info->sechdrs[i];
const char *sname = info->secstrings + s->sh_name;
if ((s->sh_flags & masks[m][0]) != masks[m][0]
|| (s->sh_flags & masks[m][1])
|| s->sh_entsize != ~0UL
|| strstarts(sname, ".init"))
continue;
s->sh_entsize = get_offset(mod, &mod->core_layout.size, s, i);
pr_debug("\t%s\n", sname);
}
switch (m) {
case 0: /* executable */
mod->core_layout.size = debug_align(mod->core_layout.size);
mod->core_layout.text_size = mod->core_layout.size;
break;
case 1: /* RO: text and ro-data */
mod->core_layout.size = debug_align(mod->core_layout.size);
mod->core_layout.ro_size = mod->core_layout.size;
break;
case 2: /* RO after init */
mod->core_layout.size = debug_align(mod->core_layout.size);
mod->core_layout.ro_after_init_size = mod->core_layout.size;
break;
case 4: /* whole core */
mod->core_layout.size = debug_align(mod->core_layout.size);
break;
}
}
pr_debug("Init section allocation order:\n");
for (m = 0; m < ARRAY_SIZE(masks); ++m) {
for (i = 0; i < info->hdr->e_shnum; ++i) {
Elf_Shdr *s = &info->sechdrs[i];
const char *sname = info->secstrings + s->sh_name;
if ((s->sh_flags & masks[m][0]) != masks[m][0]
|| (s->sh_flags & masks[m][1])
|| s->sh_entsize != ~0UL
|| !strstarts(sname, ".init"))
continue;
s->sh_entsize = (get_offset(mod, &mod->init_layout.size, s, i)
| INIT_OFFSET_MASK);
pr_debug("\t%s\n", sname);
}
switch (m) {
case 0: /* executable */
mod->init_layout.size = debug_align(mod->init_layout.size);
mod->init_layout.text_size = mod->init_layout.size;
break;
case 1: /* RO: text and ro-data */
mod->init_layout.size = debug_align(mod->init_layout.size);
mod->init_layout.ro_size = mod->init_layout.size;
break;
case 2:
/*
* RO after init doesn't apply to init_layout (only
* core_layout), so it just takes the value of ro_size.
*/
mod->init_layout.ro_after_init_size = mod->init_layout.ro_size;
break;
case 4: /* whole init */
mod->init_layout.size = debug_align(mod->init_layout.size);
break;
}
}
}
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))
pr_warn("%s: module license '%s' taints kernel.\n",
mod->name, license);
add_taint_module(mod, TAINT_PROPRIETARY_MODULE,
LOCKDEP_NOW_UNRELIABLE);
}
}
/* 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(struct load_info *info, const char *tag)
{
char *p;
unsigned int taglen = strlen(tag);
Elf_Shdr *infosec = &info->sechdrs[info->index.info];
unsigned long size = infosec->sh_size;
/*
* get_modinfo() calls made before rewrite_section_headers()
* must use sh_offset, as sh_addr isn't set!
*/
for (p = (char *)info->hdr + infosec->sh_offset; 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, struct load_info *info)
{
struct module_attribute *attr;
int i;
for (i = 0; (attr = modinfo_attrs[i]); i++) {
if (attr->setup)
attr->setup(mod, get_modinfo(info, attr->attr.name));
}
}
static void free_modinfo(struct module *mod)
{
struct module_attribute *attr;
int i;
for (i = 0; (attr = modinfo_attrs[i]); i++) {
if (attr->free)
attr->free(mod);
}
}
#ifdef CONFIG_KALLSYMS
/* Lookup exported symbol in given range of kernel_symbols */
static const struct kernel_symbol *lookup_exported_symbol(const char *name,
const struct kernel_symbol *start,
const struct kernel_symbol *stop)
{
return bsearch(name, start, stop - start,
sizeof(struct kernel_symbol), cmp_name);
}
static int is_exported(const char *name, unsigned long value,
const struct module *mod)
{
const struct kernel_symbol *ks;
if (!mod)
ks = lookup_exported_symbol(name, __start___ksymtab, __stop___ksymtab);
else
ks = lookup_exported_symbol(name, mod->syms, mod->syms + mod->num_syms);
return ks != NULL && kernel_symbol_value(ks) == value;
}
/* As per nm */
static char elf_type(const Elf_Sym *sym, const struct load_info *info)
{
const Elf_Shdr *sechdrs = info->sechdrs;
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 || sym->st_shndx == info->index.pcpu)
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 (strstarts(info->secstrings + sechdrs[sym->st_shndx].sh_name,
".debug")) {
return 'n';
}
return '?';
}
static bool is_core_symbol(const Elf_Sym *src, const Elf_Shdr *sechdrs,
unsigned int shnum, unsigned int pcpundx)
{
const Elf_Shdr *sec;
if (src->st_shndx == SHN_UNDEF
|| src->st_shndx >= shnum
|| !src->st_name)
return false;
#ifdef CONFIG_KALLSYMS_ALL
if (src->st_shndx == pcpundx)
return true;
#endif
sec = sechdrs + src->st_shndx;
if (!(sec->sh_flags & SHF_ALLOC)
#ifndef CONFIG_KALLSYMS_ALL
|| !(sec->sh_flags & SHF_EXECINSTR)
#endif
|| (sec->sh_entsize & INIT_OFFSET_MASK))
return false;
return true;
}
/*
* We only allocate and copy the strings needed by the parts of symtab
* we keep. This is simple, but has the effect of making multiple
* copies of duplicates. We could be more sophisticated, see
* linux-kernel thread starting with
* <73defb5e4bca04a6431392cc341112b1@localhost>.
*/
static void layout_symtab(struct module *mod, struct load_info *info)
{
Elf_Shdr *symsect = info->sechdrs + info->index.sym;
Elf_Shdr *strsect = info->sechdrs + info->index.str;
const Elf_Sym *src;
unsigned int i, nsrc, ndst, strtab_size = 0;
/* Put symbol section at end of init part of module. */
symsect->sh_flags |= SHF_ALLOC;
symsect->sh_entsize = get_offset(mod, &mod->init_layout.size, symsect,
info->index.sym) | INIT_OFFSET_MASK;
pr_debug("\t%s\n", info->secstrings + symsect->sh_name);
src = (void *)info->hdr + symsect->sh_offset;
nsrc = symsect->sh_size / sizeof(*src);
/* Compute total space required for the core symbols' strtab. */
for (ndst = i = 0; i < nsrc; i++) {
if (i == 0 || is_livepatch_module(mod) ||
is_core_symbol(src+i, info->sechdrs, info->hdr->e_shnum,
info->index.pcpu)) {
strtab_size += strlen(&info->strtab[src[i].st_name])+1;
ndst++;
}
}
/* Append room for core symbols at end of core part. */
info->symoffs = ALIGN(mod->core_layout.size, symsect->sh_addralign ?: 1);
info->stroffs = mod->core_layout.size = info->symoffs + ndst * sizeof(Elf_Sym);
mod->core_layout.size += strtab_size;
mod->core_layout.size = debug_align(mod->core_layout.size);
/* Put string table section at end of init part of module. */
strsect->sh_flags |= SHF_ALLOC;
strsect->sh_entsize = get_offset(mod, &mod->init_layout.size, strsect,
info->index.str) | INIT_OFFSET_MASK;
pr_debug("\t%s\n", info->secstrings + strsect->sh_name);
/* We'll tack temporary mod_kallsyms on the end. */
mod->init_layout.size = ALIGN(mod->init_layout.size,
__alignof__(struct mod_kallsyms));
info->mod_kallsyms_init_off = mod->init_layout.size;
mod->init_layout.size += sizeof(struct mod_kallsyms);
mod->init_layout.size = debug_align(mod->init_layout.size);
}
/*
* We use the full symtab and strtab which layout_symtab arranged to
* be appended to the init section. Later we switch to the cut-down
* core-only ones.
*/
static void add_kallsyms(struct module *mod, const struct load_info *info)
{
unsigned int i, ndst;
const Elf_Sym *src;
Elf_Sym *dst;
char *s;
Elf_Shdr *symsec = &info->sechdrs[info->index.sym];
/* Set up to point into init section. */
mod->kallsyms = mod->init_layout.base + info->mod_kallsyms_init_off;
mod->kallsyms->symtab = (void *)symsec->sh_addr;
mod->kallsyms->num_symtab = symsec->sh_size / sizeof(Elf_Sym);
/* Make sure we get permanent strtab: don't use info->strtab. */
mod->kallsyms->strtab = (void *)info->sechdrs[info->index.str].sh_addr;
/* Set types up while we still have access to sections. */
for (i = 0; i < mod->kallsyms->num_symtab; i++)
mod->kallsyms->symtab[i].st_size
= elf_type(&mod->kallsyms->symtab[i], info);
/* Now populate the cut down core kallsyms for after init. */
mod->core_kallsyms.symtab = dst = mod->core_layout.base + info->symoffs;
mod->core_kallsyms.strtab = s = mod->core_layout.base + info->stroffs;
src = mod->kallsyms->symtab;
for (ndst = i = 0; i < mod->kallsyms->num_symtab; i++) {
if (i == 0 || is_livepatch_module(mod) ||
is_core_symbol(src+i, info->sechdrs, info->hdr->e_shnum,
info->index.pcpu)) {
dst[ndst] = src[i];
dst[ndst++].st_name = s - mod->core_kallsyms.strtab;
s += strlcpy(s, &mod->kallsyms->strtab[src[i].st_name],
KSYM_NAME_LEN) + 1;
}
}
mod->core_kallsyms.num_symtab = ndst;
}
#else
static inline void layout_symtab(struct module *mod, struct load_info *info)
{
}
static void add_kallsyms(struct module *mod, const struct load_info *info)
{
}
#endif /* CONFIG_KALLSYMS */
static void dynamic_debug_setup(struct module *mod, struct _ddebug *debug, unsigned int num)
{
if (!debug)
return;
#ifdef CONFIG_DYNAMIC_DEBUG
if (ddebug_add_module(debug, num, mod->name))
pr_err("dynamic debug error adding module: %s\n",
debug->modname);
#endif
}
static void dynamic_debug_remove(struct module *mod, struct _ddebug *debug)
{
if