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authorLinus Torvalds <torvalds@linux-foundation.org>2008-01-29 22:45:39 +1100
committerLinus Torvalds <torvalds@linux-foundation.org>2008-01-29 22:45:39 +1100
commit03bc26cfefd6db756e6bc7fcda11dc17ada7be16 (patch)
tree36b4cdbd02e464a016d78e4b520595922d803e68
parent8cd226ca3f64f28c8123ebfaa6afe8dc8c18b174 (diff)
parent6494a93d55fad586238cc1940e846c6d03e1aaf6 (diff)
downloadlinux-03bc26cfefd6db756e6bc7fcda11dc17ada7be16.tar.gz
Merge branch 'master' of git://git.kernel.org/pub/scm/linux/kernel/git/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.
-rw-r--r--include/linux/module.h22
-rw-r--r--kernel/extable.c3
-rw-r--r--kernel/kallsyms.c11
-rw-r--r--kernel/module.c102
-rw-r--r--kernel/params.c8
5 files changed, 90 insertions, 56 deletions
diff --git a/include/linux/module.h b/include/linux/module.h
index c97bdb7eb95..aedc06be1de 100644
--- a/include/linux/module.h
+++ b/include/linux/module.h
@@ -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);
@@ -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;
}
diff --git a/kernel/extable.c b/kernel/extable.c
index 7fe26285531..a26cb2e1702 100644
--- a/kernel/extable.c
+++ b/kernel/extable.c
@@ -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;
diff --git a/kernel/kallsyms.c b/kernel/kallsyms.c
index 2fc25810509..7dadc71ce51 100644
--- a/kernel/kallsyms.c
+++ b/kernel/kallsyms.c
@@ -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);
}
/*
@@ -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;
@@ -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;
}
diff --git a/kernel/module.c b/kernel/module.c
index 1bb4c5e0d56..f6a4e721fd4 100644
--- a/kernel/module.c
+++ b/kernel/module.c
@@ -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)
@@ -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)
@@ -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);
@@ -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:
@@ -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)
@@ -1214,6 +1230,7 @@ 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",
@@ -1221,6 +1238,15 @@ int mod_sysfs_init(struct module *mod)
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));
@@ -1278,6 +1304,17 @@ static void mod_kobject_remove(struct module *mod)
}
/*
+ * 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
*/
@@ -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();
@@ -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);
@@ -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 *)
@@ -2027,7 +2069,7 @@ 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 *)
@@ -2035,7 +2077,7 @@ static struct module *load_module(void __user *umod,
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);
@@ -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);
@@ -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,
@@ -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);
@@ -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;
}
@@ -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;
}
@@ -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;
@@ -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)
diff --git a/kernel/params.c b/kernel/params.c
index 67f65ee7211..42fe5e6126c 100644
--- a/kernel/params.c
+++ b/kernel/params.c
@@ -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;
@@ -587,7 +585,7 @@ 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;
@@ -595,12 +593,12 @@ static void __init param_sysfs_builtin(void)
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;