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Merge branch 'master' of git://git.kernel.org/pub/scm/linux/kernel/gi…
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…t/rusty/linux-2.6-for-linus

* 'master' of git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux-2.6-for-linus:
  Module: check to see if we have a built in module with the same name
  module: add module taint on ndiswrapper
  module: fix the module name length in param_sysfs_builtin
  module: make module_address_lookup safe
  module: better OOPS and lockdep coverage for loading modules
  module: Fix gratuitous sprintf in module.c
  module: wait for dependent modules doing init.
  module: Don't report discarded init pages as kernel text.
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@torvalds
torvalds committed Jan 29, 2008
2 parents 8cd226c + 6494a93 commit 03bc26c
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Showing 5 changed files with 90 additions and 56 deletions.
22 changes: 13 additions & 9 deletions include/linux/module.h
View file
Expand Up @@ -446,11 +446,14 @@ static inline void __module_get(struct module *module)
__mod ? __mod->name : "kernel"; \
})

/* For kallsyms to ask for address resolution. NULL means not found. */
const char *module_address_lookup(unsigned long addr,
unsigned long *symbolsize,
unsigned long *offset,
char **modname);
/* For kallsyms to ask for address resolution. namebuf should be at
* least KSYM_NAME_LEN long: a pointer to namebuf is returned if
* found, otherwise NULL. */
char *module_address_lookup(unsigned long addr,
unsigned long *symbolsize,
unsigned long *offset,
char **modname,
char *namebuf);
int lookup_module_symbol_name(unsigned long addr, char *symname);
int lookup_module_symbol_attrs(unsigned long addr, unsigned long *size, unsigned long *offset, char *modname, char *name);

Expand Down Expand Up @@ -516,10 +519,11 @@ static inline void module_put(struct module *module)
#define module_name(mod) "kernel"

/* For kallsyms to ask for address resolution. NULL means not found. */
static inline const char *module_address_lookup(unsigned long addr,
unsigned long *symbolsize,
unsigned long *offset,
char **modname)
static inline char *module_address_lookup(unsigned long addr,
unsigned long *symbolsize,
unsigned long *offset,
char **modname,
char *namebuf)
{
return NULL;
}
Expand Down
3 changes: 2 additions & 1 deletion kernel/extable.c
View file
Expand Up @@ -46,7 +46,8 @@ int core_kernel_text(unsigned long addr)
addr <= (unsigned long)_etext)
return 1;

if (addr >= (unsigned long)_sinittext &&
if (system_state == SYSTEM_BOOTING &&
addr >= (unsigned long)_sinittext &&
addr <= (unsigned long)_einittext)
return 1;
return 0;
Expand Down
11 changes: 4 additions & 7 deletions kernel/kallsyms.c
View file
Expand Up @@ -233,10 +233,11 @@ static unsigned long get_symbol_pos(unsigned long addr,
int kallsyms_lookup_size_offset(unsigned long addr, unsigned long *symbolsize,
unsigned long *offset)
{
char namebuf[KSYM_NAME_LEN];
if (is_ksym_addr(addr))
return !!get_symbol_pos(addr, symbolsize, offset);

return !!module_address_lookup(addr, symbolsize, offset, NULL);
return !!module_address_lookup(addr, symbolsize, offset, NULL, namebuf);
}

/*
Expand All @@ -251,8 +252,6 @@ const char *kallsyms_lookup(unsigned long addr,
unsigned long *offset,
char **modname, char *namebuf)
{
const char *msym;

namebuf[KSYM_NAME_LEN - 1] = 0;
namebuf[0] = 0;

Expand All @@ -268,10 +267,8 @@ const char *kallsyms_lookup(unsigned long addr,
}

/* see if it's in a module */
msym = module_address_lookup(addr, symbolsize, offset, modname);
if (msym)
return strncpy(namebuf, msym, KSYM_NAME_LEN - 1);

return module_address_lookup(addr, symbolsize, offset, modname,
namebuf);
return NULL;
}

Expand Down
102 changes: 68 additions & 34 deletions kernel/module.c
View file
Expand Up @@ -65,6 +65,9 @@
static DEFINE_MUTEX(module_mutex);
static LIST_HEAD(modules);

/* Waiting for a module to finish initializing? */
static DECLARE_WAIT_QUEUE_HEAD(module_wq);

static BLOCKING_NOTIFIER_HEAD(module_notify_list);

int register_module_notifier(struct notifier_block * nb)
Expand All @@ -84,8 +87,11 @@ EXPORT_SYMBOL(unregister_module_notifier);
static inline int strong_try_module_get(struct module *mod)
{
if (mod && mod->state == MODULE_STATE_COMING)
return -EBUSY;
if (try_module_get(mod))
return 0;
return try_module_get(mod);
else
return -ENOENT;
}

static inline void add_taint_module(struct module *mod, unsigned flag)
Expand Down Expand Up @@ -539,11 +545,21 @@ static int already_uses(struct module *a, struct module *b)
static int use_module(struct module *a, struct module *b)
{
struct module_use *use;
int no_warn;
int no_warn, err;

if (b == NULL || already_uses(a, b)) return 1;

if (!strong_try_module_get(b))
/* If we're interrupted or time out, we fail. */
if (wait_event_interruptible_timeout(
module_wq, (err = strong_try_module_get(b)) != -EBUSY,
30 * HZ) <= 0) {
printk("%s: gave up waiting for init of module %s.\n",
a->name, b->name);
return 0;
}

/* If strong_try_module_get() returned a different error, we fail. */
if (err)
return 0;

DEBUGP("Allocating new usage for %s.\n", a->name);
Expand Down Expand Up @@ -722,7 +738,7 @@ sys_delete_module(const char __user *name_user, unsigned int flags)
mutex_lock(&module_mutex);
}
/* Store the name of the last unloaded module for diagnostic purposes */
sprintf(last_unloaded_module, mod->name);
strlcpy(last_unloaded_module, mod->name, sizeof(last_unloaded_module));
free_module(mod);

out:
Expand Down Expand Up @@ -816,7 +832,7 @@ static inline void module_unload_free(struct module *mod)

static inline int use_module(struct module *a, struct module *b)
{
return strong_try_module_get(b);
return strong_try_module_get(b) == 0;
}

static inline void module_unload_init(struct module *mod)
Expand Down Expand Up @@ -1214,13 +1230,23 @@ void module_remove_modinfo_attrs(struct module *mod)
int mod_sysfs_init(struct module *mod)
{
int err;
struct kobject *kobj;

if (!module_sysfs_initialized) {
printk(KERN_ERR "%s: module sysfs not initialized\n",
mod->name);
err = -EINVAL;
goto out;
}

kobj = kset_find_obj(module_kset, mod->name);
if (kobj) {
printk(KERN_ERR "%s: module is already loaded\n", mod->name);
kobject_put(kobj);
err = -EINVAL;
goto out;
}

mod->mkobj.mod = mod;

memset(&mod->mkobj.kobj, 0, sizeof(mod->mkobj.kobj));
Expand Down Expand Up @@ -1277,6 +1303,17 @@ static void mod_kobject_remove(struct module *mod)
kobject_put(&mod->mkobj.kobj);
}

/*
* link the module with the whole machine is stopped with interrupts off
* - this defends against kallsyms not taking locks
*/
static int __link_module(void *_mod)
{
struct module *mod = _mod;
list_add(&mod->list, &modules);
return 0;
}

/*
* unlink the module with the whole machine is stopped with interrupts off
* - this defends against kallsyms not taking locks
Expand Down Expand Up @@ -1326,7 +1363,7 @@ void *__symbol_get(const char *symbol)

preempt_disable();
value = __find_symbol(symbol, &owner, &crc, 1);
if (value && !strong_try_module_get(owner))
if (value && strong_try_module_get(owner) != 0)
value = 0;
preempt_enable();

Expand Down Expand Up @@ -1889,7 +1926,7 @@ static struct module *load_module(void __user *umod,
set_license(mod, get_modinfo(sechdrs, infoindex, "license"));

if (strcmp(mod->name, "ndiswrapper") == 0)
add_taint(TAINT_PROPRIETARY_MODULE);
add_taint_module(mod, TAINT_PROPRIETARY_MODULE);
if (strcmp(mod->name, "driverloader") == 0)
add_taint_module(mod, TAINT_PROPRIETARY_MODULE);

Expand Down Expand Up @@ -2019,6 +2056,11 @@ static struct module *load_module(void __user *umod,
printk(KERN_WARNING "%s: Ignoring obsolete parameters\n",
mod->name);

/* Now sew it into the lists so we can get lockdep and oops
* info during argument parsing. Noone should access us, since
* strong_try_module_get() will fail. */
stop_machine_run(__link_module, mod, NR_CPUS);

/* Size of section 0 is 0, so this works well if no params */
err = parse_args(mod->name, mod->args,
(struct kernel_param *)
Expand All @@ -2027,15 +2069,15 @@ static struct module *load_module(void __user *umod,
/ sizeof(struct kernel_param),
NULL);
if (err < 0)
goto arch_cleanup;
goto unlink;

err = mod_sysfs_setup(mod,
(struct kernel_param *)
sechdrs[setupindex].sh_addr,
sechdrs[setupindex].sh_size
/ sizeof(struct kernel_param));
if (err < 0)
goto arch_cleanup;
goto unlink;
add_sect_attrs(mod, hdr->e_shnum, secstrings, sechdrs);
add_notes_attrs(mod, hdr->e_shnum, secstrings, sechdrs);

Expand All @@ -2050,7 +2092,8 @@ static struct module *load_module(void __user *umod,
/* Done! */
return mod;

arch_cleanup:
unlink:
stop_machine_run(__unlink_module, mod, NR_CPUS);
module_arch_cleanup(mod);
cleanup:
kobject_del(&mod->mkobj.kobj);
Expand All @@ -2075,17 +2118,6 @@ static struct module *load_module(void __user *umod,
goto free_hdr;
}

/*
* link the module with the whole machine is stopped with interrupts off
* - this defends against kallsyms not taking locks
*/
static int __link_module(void *_mod)
{
struct module *mod = _mod;
list_add(&mod->list, &modules);
return 0;
}

/* This is where the real work happens */
asmlinkage long
sys_init_module(void __user *umod,
Expand All @@ -2110,10 +2142,6 @@ sys_init_module(void __user *umod,
return PTR_ERR(mod);
}

/* Now sew it into the lists. They won't access us, since
strong_try_module_get() will fail. */
stop_machine_run(__link_module, mod, NR_CPUS);

/* Drop lock so they can recurse */
mutex_unlock(&module_mutex);

Expand All @@ -2132,6 +2160,7 @@ sys_init_module(void __user *umod,
mutex_lock(&module_mutex);
free_module(mod);
mutex_unlock(&module_mutex);
wake_up(&module_wq);
return ret;
}

Expand All @@ -2146,6 +2175,7 @@ sys_init_module(void __user *umod,
mod->init_size = 0;
mod->init_text_size = 0;
mutex_unlock(&module_mutex);
wake_up(&module_wq);

return 0;
}
Expand Down Expand Up @@ -2210,14 +2240,13 @@ static const char *get_ksymbol(struct module *mod,
return mod->strtab + mod->symtab[best].st_name;
}

/* For kallsyms to ask for address resolution. NULL means not found.
We don't lock, as this is used for oops resolution and races are a
lesser concern. */
/* FIXME: Risky: returns a pointer into a module w/o lock */
const char *module_address_lookup(unsigned long addr,
unsigned long *size,
unsigned long *offset,
char **modname)
/* For kallsyms to ask for address resolution. NULL means not found. Careful
* not to lock to avoid deadlock on oopses, simply disable preemption. */
char *module_address_lookup(unsigned long addr,
unsigned long *size,
unsigned long *offset,
char **modname,
char *namebuf)
{
struct module *mod;
const char *ret = NULL;
Expand All @@ -2232,8 +2261,13 @@ const char *module_address_lookup(unsigned long addr,
break;
}
}
/* Make a copy in here where it's safe */
if (ret) {
strncpy(namebuf, ret, KSYM_NAME_LEN - 1);
ret = namebuf;
}
preempt_enable();
return ret;
return (char *)ret;
}

int lookup_module_symbol_name(unsigned long addr, char *symname)
Expand Down
8 changes: 3 additions & 5 deletions kernel/params.c
View file
Expand Up @@ -376,8 +376,6 @@ int param_get_string(char *buffer, struct kernel_param *kp)

extern struct kernel_param __start___param[], __stop___param[];

#define MAX_KBUILD_MODNAME KOBJ_NAME_LEN

struct param_attribute
{
struct module_attribute mattr;
Expand Down Expand Up @@ -587,20 +585,20 @@ static void __init param_sysfs_builtin(void)
{
struct kernel_param *kp, *kp_begin = NULL;
unsigned int i, name_len, count = 0;
char modname[MAX_KBUILD_MODNAME + 1] = "";
char modname[MODULE_NAME_LEN + 1] = "";

for (i=0; i < __stop___param - __start___param; i++) {
char *dot;
size_t max_name_len;

kp = &__start___param[i];
max_name_len =
min_t(size_t, MAX_KBUILD_MODNAME, strlen(kp->name));
min_t(size_t, MODULE_NAME_LEN, strlen(kp->name));

dot = memchr(kp->name, '.', max_name_len);
if (!dot) {
DEBUGP("couldn't find period in first %d characters "
"of %s\n", MAX_KBUILD_MODNAME, kp->name);
"of %s\n", MODULE_NAME_LEN, kp->name);
continue;
}
name_len = dot - kp->name;
Expand Down

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