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Merge git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux-2.6-for-linus

Browse Source 
* git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux-2.6-for-linus:
  module: add MODULE_STATE_GOING notifier call
  module: Enhance verify_export_symbols
  module: set unused_gpl_crcs instead of overwriting unused_crcs
  module: neaten __find_symbol, rename to find_symbol
  module: reduce module image and resident size
  module: make module_sect_attrs private to kernel/module.c
This commit is contained in:
Linus Torvalds 2008-05-01 08:26:56 -07:00
commit 03fc922f40
2 changed files with 172 additions and 166 deletions
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19
include/linux/module.h
View File

@ -190,7 +190,7 @@ void *__symbol_get_gpl(const char *symbol);
extern typeof(sym) sym; \
__CRC_SYMBOL(sym, sec) \
static const char __kstrtab_##sym[] \
__attribute__((section("__ksymtab_strings"))) \
__attribute__((section("__ksymtab_strings"), aligned(1))) \
= MODULE_SYMBOL_PREFIX #sym; \
static const struct kernel_symbol __ksymtab_##sym \
__used \
@ -229,23 +229,6 @@ enum module_state
MODULE_STATE_GOING,
};
/* Similar stuff for section attributes. */
struct module_sect_attr
{
struct module_attribute mattr;
char *name;
unsigned long address;
};
struct module_sect_attrs
{
struct attribute_group grp;
int nsections;
struct module_sect_attr attrs[0];
};
struct module_param_attrs;
struct module
{
enum module_state state;

319
kernel/module.c
View File

@ -164,131 +164,140 @@ static const struct kernel_symbol *lookup_symbol(const char *name,
return NULL;
}
static void printk_unused_warning(const char *name)
static bool always_ok(bool gplok, bool warn, const char *name)
{
printk(KERN_WARNING "Symbol %s is marked as UNUSED, "
"however this module is using it.\n", name);
printk(KERN_WARNING "This symbol will go away in the future.\n");
printk(KERN_WARNING "Please evalute if this is the right api to use, "
"and if it really is, submit a report the linux kernel "
"mailinglist together with submitting your code for "
"inclusion.\n");
return true;
}
/* 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)
static bool printk_unused_warning(bool gplok, bool warn, const char *name)
{
if (warn) {
printk(KERN_WARNING "Symbol %s is marked as UNUSED, "
"however this module is using it.\n", name);
printk(KERN_WARNING
"This symbol will go away in the future.\n");
printk(KERN_WARNING
"Please evalute if this is the right api to use and if "
"it really is, submit a report the linux kernel "
"mailinglist together with submitting your code for "
"inclusion.\n");
}
return true;
}
static bool gpl_only_unused_warning(bool gplok, bool warn, const char *name)
{
if (!gplok)
return false;
return printk_unused_warning(gplok, warn, name);
}
static bool gpl_only(bool gplok, bool warn, const char *name)
{
return gplok;
}
static bool warn_if_not_gpl(bool gplok, bool warn, const char *name)
{
if (!gplok && warn) {
printk(KERN_WARNING "Symbol %s is being used "
"by a non-GPL module, which will not "
"be allowed in the future\n", name);
printk(KERN_WARNING "Please see the file "
"Documentation/feature-removal-schedule.txt "
"in the kernel source tree for more details.\n");
}
return true;
}
struct symsearch {
const struct kernel_symbol *start, *stop;
const unsigned long *crcs;
bool (*check)(bool gplok, bool warn, const char *name);
};
/* Look through this array of symbol tables for a symbol match which
* passes the check function. */
static const struct kernel_symbol *search_symarrays(const struct symsearch *arr,
unsigned int num,
const char *name,
bool gplok,
bool warn,
const unsigned long **crc)
{
unsigned int i;
const struct kernel_symbol *ks;
for (i = 0; i < num; i++) {
ks = lookup_symbol(name, arr[i].start, arr[i].stop);
if (!ks || !arr[i].check(gplok, warn, name))
continue;
if (crc)
*crc = symversion(arr[i].crcs, ks - arr[i].start);
return ks;
}
return NULL;
}
/* Find a symbol, return value, (optional) crc and (optional) module
* which owns it */
static unsigned long find_symbol(const char *name,
struct module **owner,
const unsigned long **crc,
bool gplok,
bool warn)
{
struct module *mod;
const struct kernel_symbol *ks;
const struct symsearch arr[] = {
{ __start___ksymtab, __stop___ksymtab, __start___kcrctab,
always_ok },
{ __start___ksymtab_gpl, __stop___ksymtab_gpl,
__start___kcrctab_gpl, gpl_only },
{ __start___ksymtab_gpl_future, __stop___ksymtab_gpl_future,
__start___kcrctab_gpl_future, warn_if_not_gpl },
{ __start___ksymtab_unused, __stop___ksymtab_unused,
__start___kcrctab_unused, printk_unused_warning },
{ __start___ksymtab_unused_gpl, __stop___ksymtab_unused_gpl,
__start___kcrctab_unused_gpl, gpl_only_unused_warning },
};
/* Core kernel first. */
*owner = NULL;
ks = lookup_symbol(name, __start___ksymtab, __stop___ksymtab);
ks = search_symarrays(arr, ARRAY_SIZE(arr), name, gplok, warn, crc);
if (ks) {
*crc = symversion(__start___kcrctab, (ks - __start___ksymtab));
return ks->value;
}
if (gplok) {
ks = lookup_symbol(name, __start___ksymtab_gpl,
__stop___ksymtab_gpl);
if (ks) {
*crc = symversion(__start___kcrctab_gpl,
(ks - __start___ksymtab_gpl));
return ks->value;
}
}
ks = lookup_symbol(name, __start___ksymtab_gpl_future,
__stop___ksymtab_gpl_future);
if (ks) {
if (!gplok) {
printk(KERN_WARNING "Symbol %s is being used "
"by a non-GPL module, which will not "
"be allowed in the future\n", name);
printk(KERN_WARNING "Please see the file "
"Documentation/feature-removal-schedule.txt "
"in the kernel source tree for more "
"details.\n");
}
*crc = symversion(__start___kcrctab_gpl_future,
(ks - __start___ksymtab_gpl_future));
return ks->value;
}
ks = lookup_symbol(name, __start___ksymtab_unused,
__stop___ksymtab_unused);
if (ks) {
printk_unused_warning(name);
*crc = symversion(__start___kcrctab_unused,
(ks - __start___ksymtab_unused));
return ks->value;
}
if (gplok)
ks = lookup_symbol(name, __start___ksymtab_unused_gpl,
__stop___ksymtab_unused_gpl);
if (ks) {
printk_unused_warning(name);
*crc = symversion(__start___kcrctab_unused_gpl,
(ks - __start___ksymtab_unused_gpl));
if (owner)
*owner = NULL;
return ks->value;
}
/* Now try modules. */
list_for_each_entry(mod, &modules, list) {
*owner = mod;
ks = lookup_symbol(name, mod->syms, mod->syms + mod->num_syms);
if (ks) {
*crc = symversion(mod->crcs, (ks - mod->syms));
return ks->value;
}
struct symsearch arr[] = {
{ mod->syms, mod->syms + mod->num_syms, mod->crcs,
always_ok },
{ mod->gpl_syms, mod->gpl_syms + mod->num_gpl_syms,
mod->gpl_crcs, gpl_only },
{ mod->gpl_future_syms,
mod->gpl_future_syms + mod->num_gpl_future_syms,
mod->gpl_future_crcs, warn_if_not_gpl },
{ mod->unused_syms,
mod->unused_syms + mod->num_unused_syms,
mod->unused_crcs, printk_unused_warning },
{ mod->unused_gpl_syms,
mod->unused_gpl_syms + mod->num_unused_gpl_syms,
mod->unused_gpl_crcs, gpl_only_unused_warning },
};
if (gplok) {
ks = lookup_symbol(name, mod->gpl_syms,
mod->gpl_syms + mod->num_gpl_syms);
if (ks) {
*crc = symversion(mod->gpl_crcs,
(ks - mod->gpl_syms));
return ks->value;
}
}
ks = lookup_symbol(name, mod->unused_syms, mod->unused_syms + mod->num_unused_syms);
ks = search_symarrays(arr, ARRAY_SIZE(arr),
name, gplok, warn, crc);
if (ks) {
printk_unused_warning(name);
*crc = symversion(mod->unused_crcs, (ks - mod->unused_syms));
return ks->value;
}
if (gplok) {
ks = lookup_symbol(name, mod->unused_gpl_syms,
mod->unused_gpl_syms + mod->num_unused_gpl_syms);
if (ks) {
printk_unused_warning(name);
*crc = symversion(mod->unused_gpl_crcs,
(ks - mod->unused_gpl_syms));
return ks->value;
}
}
ks = lookup_symbol(name, mod->gpl_future_syms,
(mod->gpl_future_syms +
mod->num_gpl_future_syms));
if (ks) {
if (!gplok) {
printk(KERN_WARNING "Symbol %s is being used "
"by a non-GPL module, which will not "
"be allowed in the future\n", name);
printk(KERN_WARNING "Please see the file "
"Documentation/feature-removal-schedule.txt "
"in the kernel source tree for more "
"details.\n");
}
*crc = symversion(mod->gpl_future_crcs,
(ks - mod->gpl_future_syms));
if (owner)
*owner = mod;
return ks->value;
}
}
DEBUGP("Failed to find symbol %s\n", name);
return -ENOENT;
}
@ -736,12 +745,13 @@ sys_delete_module(const char __user *name_user, unsigned int flags)
if (!forced && module_refcount(mod) != 0)
wait_for_zero_refcount(mod);
mutex_unlock(&module_mutex);
/* Final destruction now noone is using it. */
if (mod->exit != NULL) {
mutex_unlock(&module_mutex);
if (mod->exit != NULL)
mod->exit();
mutex_lock(&module_mutex);
}
blocking_notifier_call_chain(&module_notify_list,
MODULE_STATE_GOING, mod);
mutex_lock(&module_mutex);
/* Store the name of the last unloaded module for diagnostic purposes */
strlcpy(last_unloaded_module, mod->name, sizeof(last_unloaded_module));
free_module(mod);
@ -777,10 +787,9 @@ static void print_unload_info(struct seq_file *m, struct module *mod)
void __symbol_put(const char *symbol)
{
struct module *owner;
const unsigned long *crc;
preempt_disable();
if (IS_ERR_VALUE(__find_symbol(symbol, &owner, &crc, 1)))
if (IS_ERR_VALUE(find_symbol(symbol, &owner, NULL, true, false)))
BUG();
module_put(owner);
preempt_enable();
@ -924,13 +933,10 @@ static inline int check_modstruct_version(Elf_Shdr *sechdrs,
struct module *mod)
{
const unsigned long *crc;
struct module *owner;
if (IS_ERR_VALUE(__find_symbol("struct_module",
&owner, &crc, 1)))
if (IS_ERR_VALUE(find_symbol("struct_module", NULL, &crc, true, false)))
BUG();
return check_version(sechdrs, versindex, "struct_module", mod,
crc);
return check_version(sechdrs, versindex, "struct_module", mod, crc);
}
/* First part is kernel version, which we ignore. */
@ -974,8 +980,8 @@ static unsigned long resolve_symbol(Elf_Shdr *sechdrs,
unsigned long ret;
const unsigned long *crc;
ret = __find_symbol(name, &owner, &crc,
!(mod->taints & TAINT_PROPRIETARY_MODULE));
ret = find_symbol(name, &owner, &crc,
!(mod->taints & TAINT_PROPRIETARY_MODULE), true);
if (!IS_ERR_VALUE(ret)) {
/* use_module can fail due to OOM,
or module initialization or unloading */
@ -991,6 +997,20 @@ static unsigned long resolve_symbol(Elf_Shdr *sechdrs,
* J. Corbet <corbet@lwn.net>
*/
#if defined(CONFIG_KALLSYMS) && defined(CONFIG_SYSFS)
struct module_sect_attr
{
struct module_attribute mattr;
char *name;
unsigned long address;
};
struct module_sect_attrs
{
struct attribute_group grp;
unsigned int nsections;
struct module_sect_attr attrs[0];
};
static ssize_t module_sect_show(struct module_attribute *mattr,
struct module *mod, char *buf)
{
@ -1001,7 +1021,7 @@ static ssize_t module_sect_show(struct module_attribute *mattr,
static void free_sect_attrs(struct module_sect_attrs *sect_attrs)
{
int section;
unsigned int section;
for (section = 0; section < sect_attrs->nsections; section++)
kfree(sect_attrs->attrs[section].name);
@ -1362,10 +1382,9 @@ void *__symbol_get(const char *symbol)
{
struct module *owner;
unsigned long value;
const unsigned long *crc;
preempt_disable();
value = __find_symbol(symbol, &owner, &crc, 1);
value = find_symbol(symbol, &owner, NULL, true, true);
if (IS_ERR_VALUE(value))
value = 0;
else if (strong_try_module_get(owner))
@ -1382,33 +1401,33 @@ EXPORT_SYMBOL_GPL(__symbol_get);
*/
static int verify_export_symbols(struct module *mod)
{
const char *name = NULL;
unsigned long i, ret = 0;
unsigned int i;
struct module *owner;
const unsigned long *crc;
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 },
{ mod->unused_syms, mod->num_unused_syms },
{ mod->unused_gpl_syms, mod->num_unused_gpl_syms },
};
for (i = 0; i < mod->num_syms; i++)
if (!IS_ERR_VALUE(__find_symbol(mod->syms[i].name,
&owner, &crc, 1))) {
name = mod->syms[i].name;
ret = -ENOEXEC;
goto dup;
for (i = 0; i < ARRAY_SIZE(arr); i++) {
for (s = arr[i].sym; s < arr[i].sym + arr[i].num; s++) {
if (!IS_ERR_VALUE(find_symbol(s->name, &owner,
NULL, true, false))) {
printk(KERN_ERR
"%s: exports duplicate symbol %s"
" (owned by %s)\n",
mod->name, s->name, module_name(owner));
return -ENOEXEC;
}
}
for (i = 0; i < mod->num_gpl_syms; i++)
if (!IS_ERR_VALUE(__find_symbol(mod->gpl_syms[i].name,
&owner, &crc, 1))) {
name = mod->gpl_syms[i].name;
ret = -ENOEXEC;
goto dup;
}
dup:
if (ret)
printk(KERN_ERR "%s: exports duplicate symbol %s (owned by %s)\n",
mod->name, name, module_name(owner));
return ret;
}
return 0;
}
/* Change all symbols so that st_value encodes the pointer directly. */
@ -1814,8 +1833,9 @@ static struct module *load_module(void __user *umod,
unwindex = find_sec(hdr, sechdrs, secstrings, ARCH_UNWIND_SECTION_NAME);
#endif
/* Don't keep modinfo section */
/* Don't keep modinfo and version sections. */
sechdrs[infoindex].sh_flags &= ~(unsigned long)SHF_ALLOC;
sechdrs[versindex].sh_flags &= ~(unsigned long)SHF_ALLOC;
#ifdef CONFIG_KALLSYMS
/* Keep symbol and string tables for decoding later. */
sechdrs[symindex].sh_flags |= SHF_ALLOC;
@ -1977,7 +1997,8 @@ static struct module *load_module(void __user *umod,
mod->unused_crcs = (void *)sechdrs[unusedcrcindex].sh_addr;
mod->unused_gpl_syms = (void *)sechdrs[unusedgplindex].sh_addr;
if (unusedgplcrcindex)
mod->unused_crcs = (void *)sechdrs[unusedgplcrcindex].sh_addr;
mod->unused_gpl_crcs
= (void *)sechdrs[unusedgplcrcindex].sh_addr;
#ifdef CONFIG_MODVERSIONS
if ((mod->num_syms && !crcindex) ||
@ -2171,6 +2192,8 @@ sys_init_module(void __user *umod,
mod->state = MODULE_STATE_GOING;
synchronize_sched();
module_put(mod);
blocking_notifier_call_chain(&module_notify_list,
MODULE_STATE_GOING, mod);
mutex_lock(&module_mutex);
free_module(mod);
mutex_unlock(&module_mutex);